cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A153301 Coefficient of x^(4n+1)/(4n+1)! in the Maclaurin expansion of sm4(x), which is a generalization of the Dixon elliptic function sm(x,0) defined by A104133.

Original entry on oeis.org

1, 18, 14364, 70203672, 1192064637456, 52269828456672288, 4930307288899134335424, 884135650165992118901204352, 275721138550891190637445080842496
Offset: 0

Views

Author

Paul D. Hanna, Jan 02 2009

Keywords

Comments

Equals column 0 of triangle A357800.

Examples

			G.f.: sm4(x) = x + 18*x^5/5! + 14364*x^9/9! + 70203672*x^13/13! + 1192064637456*x^17/17! +...
cm4(x) = 1 + 6*x^4/4! + 2268*x^8/8! + 7434504*x^12/12! + 95227613712*x^16/16! +...
These functions satisfy: cm4(x)^4 - sm4(x)^4 = 1 where:
sm4(x)^4 = 24*x^4/4! + 24192*x^8/8! + 140507136*x^12/12! + 2716743794688*x^16/16! +...
RELATED EXPANSIONS:
sm4(x)^2 = 2*x^2/2! + 216*x^6/6! + 368928*x^10/10! + 3000945024*x^14/14! +...
cm4(x)^2 = 1 + 12*x^4/4! + 7056*x^8/8! + 28340928*x^12/12! + 419025809664*x^16/16! +...
sm4(x)^3 = 6*x^3/3! + 2268*x^7/7! + 7434504*x^11/11! + 95227613712*x^15/15! +...
cm4(x)^3 = 1 + 18*x^4/4! + 14364*x^8/8! + 70203672*x^12/12! + 1192064637456*x^16/16! +...
DERIVATIVES:
d/dx sm4(x) = cm4(x)^3 ;
d^2/dx^2 sm4(x) = 3*sm4(x)^3*cm4(x)^2 ;
d^3/dx^3 sm4(x) = 6*sm4(x)^6*cm4(x) + 9*sm4(x)^2*cm4(x)^5 ;
d^4/dx^4 sm4(x) = 6*sm4(x)^9 + 81*sm4(x)^5*cm4(x)^4 + 18*sm4(x)*cm4(x)^8 ;...

Links

Crossrefs

Cf. A104133; A153300, A153302 (cm4(x)^2 + sm4(x)^2).
Cf. A357800.

Programs

  • Mathematica
    With[{n = 8}, CoefficientList[Series[JacobiSN[Sqrt[2] x^(1/4), 1/2]/(x^(1/4) Sqrt[2 JacobiCN[Sqrt[2] x^(1/4), 1/2]]), {x, 0, n}], x] Table[(4 k + 1)!, {k, 0, n}]] (* Jan Mangaldan, Jan 04 2017 *)
  • PARI
    {a(n)=local(A);if(n<0,0,A=x*O(x);for(i=0,n,A=intformal((1+intformal(A^3))^3));n=4*n+1;n!*polcoeff(A,n))}

Formula

Define cm4(x)^4 = 1 + sm4(x)^4, where cm4(x) is the g.f. of A153300, then:
d/dx sm4(x) = cm4(x)^3 ;
d/dx cm4(x) = sm4(x)^3 .

A357540 Coefficients T(n,k) of x^(3*n+1)*r^(3*k)/(3*n+1)! in power series S(x,r) = Integral C(x,r)^2 * D(x,r)^2 dx such that C(x,r)^3 - S(x,r)^3 = 1 and D(x,r)^3 - r^3*S(x,r)^3 = 1, as a symmetric triangle read by rows.

Original entry on oeis.org

1, 4, 4, 160, 800, 160, 20800, 292800, 292800, 20800, 6476800, 191910400, 500121600, 191910400, 6476800, 3946624000, 210590336000, 1091343616000, 1091343616000, 210590336000, 3946624000, 4161608704000, 361556726784000, 3216369361920000, 6333406238720000, 3216369361920000, 361556726784000, 4161608704000, 6974121256960000, 919365914368000000, 12789764316088320000, 42703786876467200000
Offset: 0

Views

Author

Paul D. Hanna, Oct 09 2022

Keywords

Comments

Related to Dixon elliptic function sm(x,0) (cf. A104133).

Examples

			E.g.f.: S(x,r) = Sum_{n>=0} T(n,k) * x^(3*n+1) * r^(3*k) / (3*n+1)! begins:
S(x,r) = Integral C(x,r)^2 * D(x,r)^2 dx = x + (4 + 4*r^3)*x^4/4! + (160 + 800*r^3 + 160*r^6)*x^7/7! + (20800 + 292800*r^3 + 292800*r^6 + 20800*r^9)*x^10/10! + (6476800 + 191910400*r^3 + 500121600*r^6 + 191910400*r^9 + 6476800*r^12)*x^13/13! + (3946624000 + 210590336000*r^3 + 1091343616000*r^6 + 1091343616000*r^9 + 210590336000*r^12 + 3946624000*r^15)*x^16/16! + (4161608704000 + 361556726784000*r^3 + 3216369361920000*r^6 + 6333406238720000*r^9 + 3216369361920000*r^12 + 361556726784000*r^15 + 4161608704000*r^18)*x^19/19! + (6974121256960000 + 919365914368000000*r^3 + 12789764316088320000*r^6 + 42703786876467200000*r^9 + 42703786876467200000*r^12 + 12789764316088320000*r^15 + 919365914368000000*r^18 + 6974121256960000*r^21)*x^22/22! + ...
This table of coefficients T(n,k) of x^(3*n+1) * r^(3*k) / (3*n+1)! in S(x,r) for n >= 0, k = 0..n, begins:
n = 0: [1];
n = 1: [4, 4];
n = 2: [160, 800, 160];
n = 3: [20800, 292800, 292800, 20800];
n = 4: [6476800, 191910400, 500121600, 191910400, 6476800];
n = 5: [3946624000, 210590336000, 1091343616000, 1091343616000, 210590336000, 3946624000];
n = 6: [4161608704000, 361556726784000, 3216369361920000, 6333406238720000, 3216369361920000, 361556726784000, 4161608704000];
n = 7: [6974121256960000, 919365914368000000, 12789764316088320000, 42703786876467200000, 42703786876467200000, 12789764316088320000, 919365914368000000, 6974121256960000];
n = 8: [17455222222028800000, 3313522085749145600000, 67574136526308966400000, 348431220691544883200000, 588750579021316096000000, 348431220691544883200000, 67574136526308966400000, 3313522085749145600000, 17455222222028800000];
...
in which both column 0 and the main diagoal give the unsigned coefficients in the Dixon elliptic function sm(x,0) (cf. A104133).
RELATED SERIES.
C(x,r) = 1 + Integral S(x,r)^2 * D(x,r)^2 dx = 1 + 2*x^3/3! + (40 + 120*r^3)*x^6/6! + (3680 + 37440*r^3 + 21600*r^6)*x^9/9! + (880000 + 20592000*r^3 + 38966400*r^6 + 8553600*r^9)*x^12/12! + (435776000 + 19269888000*r^3 + 79491456000*r^6 + 57708288000*r^9 + 6329664000*r^12)*x^15/15! + (386949376000 + 28748332800000*r^3 + 213892766208000*r^6 + 335872728576000*r^9 + 123646051584000*r^12 + 7852204800000*r^15)*x^18/18! + (560034421760000 + 64544356546560000*r^3 + 774705298498560000*r^6 + 2169194182594560000*r^9 + 1730103155573760000*r^12 + 374841224017920000*r^15 + 15132769090560000*r^18)*x^21/21! + ...
where C(x,r)^3 - S(x,r)^3 = 1.
D(x,r) = 1 + r^3 * Integral S(x,r)^2 * C(x,r)^2 dx = 1 + 2*r^3*x^3/3! + (120*r^3 + 40*r^6)*x^6/6! + (21600*r^3 + 37440*r^6 + 3680*r^9)*x^9/9! + (8553600*r^3 + 38966400*r^6 + 20592000*r^9 + 880000*r^12)*x^12/12! + (6329664000*r^3 + 57708288000*r^6 + 79491456000*r^9 + 19269888000*r^12 + 435776000*r^15)*x^15/15! + (7852204800000*r^3 + 123646051584000*r^6 + 335872728576000*r^9 + 213892766208000*r^12 + 28748332800000*r^15 + 386949376000*r^18)*x^18/18! + (15132769090560000*r^3 + 374841224017920000*r^6 + 1730103155573760000*r^9 + 2169194182594560000*r^12 + 774705298498560000*r^15 + 64544356546560000*r^18 + 560034421760000*r^21)*x^21/21! + ...
where D(x,r)^3 - r^3 * S(x,r)^3 = 1.

Links

Crossrefs

Cf. A104133 (sm(x,0)), A357541 (C(x,r)), A357542 (D(x,r)), A357543 (row sums), A357544 (central terms).
Cf. A357800.

Programs

  • PARI
    {T(n,k) = my(S=x,C=1,D=1); for(i=0,n,
S = intformal( C^2*D^2 +O(x^(3*n+3)));
C = 1 + intformal( S^2*D^2);
D = 1 + r^3*intformal( S^2*C^2); );
(3*n+1)!*polcoeff( polcoeff(S,3*n+1,x),3*k,r)}
for(n=0,10, for(k=0,n, print1( T(n,k),", "));print(""))
  • PARI
    /* Using Series Reversion (faster) */
{T(n,k) = my(S = serreverse( intformal( 1/((1 + x^3)^2*(1 + r^3*x^3)^2 +O(x^(3*n+3)) )^(1/3) )) );
(3*n+1)!*polcoeff( polcoeff(S,3*n+1,x),3*k,r)}
for(n=0,10, for(k=0,n, print1( T(n,k),", "));print(""))

Formula

Generating function S(x,r) = Sum_{n>=0} Sum_{k=0..n} T(n,k) * x^(3*n+1) * r^(3*k) / (3*n+1)! and related functions C(x,r) and D(x,r) satisfy the following formulas.
For brevity, some formulas here will use S = S(x,r), C = C(x,r), and D = D(x,r).
(1.a) C(x,r)^3 - S(x,r)^3 = 1.
(1.b) D(x,r)^3 - r^3 * S(x,r)^3 = 1.
(1.c) D(x,r)^3 - r^3 * C(x,r)^3 = 1 - r^3.
Integral formulas.
(2.a) S(x,r) = Integral C(x,r)^2 * D(x,r)^2 dx.
(2.b) C(x,r) = 1 + Integral S(x,r)^2 * D(x,r)^2 dx.
(2.c) D(x,r) = 1 + r^3 * Integral S(x,r)^2 * C(x,r)^2 dx.
(2.d) S(x,r)^3 = Integral 3 * S(x,r)^2 * C(x,r)^2 * D(x,r)^2 dx.
Derivatives.
(3.a) d/dx S(x,r) = C(x,r)^2 * D(x,r)^2.
(3.b) d/dx C(x,r) = S(x,r)^2 * D(x,r)^2.
(3.c) d/dx D(x,r) = r^3 * S(x,r)^2 * C(x,r)^2.
Exponential formulas.
(4.a) C - S = exp( -Integral (C + S) * D^2 dx ).
(4.b) D - r*S = exp( -r * Integral (D + r*S) * C^2 dx ).
(4.c) C + S = sqrt(C^2 - S^2) * exp( Integral D^2/(C^2 - S^2) dx ).
(4.d) D + r*S = sqrt(D^2 - r^2*S^2) * exp( r * Integral C^2/(D^2 - r^2*S^2) dx ).
(5.a) C^2 - S^2 = exp( -2 * Integral S*C/(C + S) * D^2 dx ).
(5.b) D^2 - r^2*S^2 = exp( -2*r^2 * Integral S*D/(D + r*S) * C^2 dx ).
(5.c) C^2 + S^2 = exp( 2 * Integral S*C*(C + S)/(C^2 + S^2) * D^2 dx ).
(5.d) D^2 + r^2*S^2 = exp( 2*r^2 * Integral S*D*(D + r*S)/(D^2 + r^2*S^2) * C^2 dx ).
Hyperbolic functions.
(6.a) C = sqrt(C^2 - S^2) * cosh( Integral D^2/(C^2 - S^2) dx ).
(6.b) S = sqrt(C^2 - S^2) * sinh( Integral D^2/(C^2 - S^2) dx ).
(6.c) D = sqrt(D^2 - r^2*S^2) * cosh( r * Integral C^2/(D^2 - r^2*S^2) dx ).
(6.d) r*S = sqrt(D^2 - r^2*S^2) * sinh( r * Integral C^2/(D^2 - r^2*S^2) dx ).
Other formulas.
(7) S(x,r) = Series_Reversion( Integral ( (1 + x^3)^2 * (1 + r^3*x^3)^2 )^(-1/3) dx ).
(8.a) T(n,0) = T(n,n) = (-1)^n * A104133(n).
(8.b) Sum_{k=0..n} T(n,k) = (3*n+1)!/(3^n*n!) * Product_{k=1..n} (3*k - 2) = A357543(n), for n >= 0.

A357801 Coefficients T(n,k) of x^(4*n)*r^(4*k)/(4*n)! in power series C(x,r) = 1 + Integral S(x,r)^3 * D(x,r)^3 dx such that C(x,r)^4 - S(x,r)^4 = 1 and D(x,r)^4 - r^4*S(x,r)^4 = 1, as a triangle read by rows.

Original entry on oeis.org

1, 6, 0, 2268, 6048, 0, 7434504, 56282688, 35126784, 0, 95227613712, 1409371197696, 2514356038656, 679185948672, 0, 3354162536029536, 81696140755536384, 284770675495950336, 220415417637617664, 33022883487154176, 0, 264444869673131894208, 9583398717725834749440, 54913653475645427527680, 83079959422282198548480, 35701050229143616880640, 3393656235362623684608, 0
Offset: 0

Views

Author

Paul D. Hanna, Oct 14 2022

Keywords

Comments

Equals a row reversal of triangle A357802.

Examples

			E.g.f.: C(x,r) = Sum_{n>=0} T(n,k) * x^(4*n) * r^(4*k) / (4*n)! begins:
C(x,r) = 1 + 6*x^4/4! + (2268 + 6048*r^4)*x^8/8! + (7434504 + 56282688*r^4 + 35126784*r^8)*x^12/12! + (95227613712 + 1409371197696*r^4 + 2514356038656*r^8 + 679185948672*r^12)*x^16/16! + (3354162536029536 + 81696140755536384*r^4 + 284770675495950336*r^8 + 220415417637617664*r^12 + 33022883487154176*r^16)*x^20/20! + (264444869673131894208 + 9583398717725834749440*r^4 + 54913653475645427527680*r^8 + 83079959422282198548480*r^12 + 35701050229143616880640*r^16 + 3393656235362623684608*r^20)*x^24/24! + ...
where S(x,r) = 1 + Integral S(x,r)^3 * D(x,r)^3 dx.
TRIANGLE.
This triangle of coefficients T(n,k) of x^(4*n) * r^(4*k) / (4*n)! in C(x,r) for n >= 0, k = 0..n, begins:
n = 0: [1];
n = 1: [6, 0];
n = 2: [2268, 6048, 0];
n = 3: [7434504, 56282688, 35126784, 0];
n = 4: [95227613712, 1409371197696, 2514356038656, 679185948672, 0];
n = 5: [3354162536029536, 81696140755536384, 284770675495950336, 220415417637617664, 33022883487154176, 0];
n = 6: [264444869673131894208, 9583398717725834749440, 54913653475645427527680, 83079959422282198548480, 35701050229143616880640, 3393656235362623684608, 0]; ...
in which column 0 equals A153300.
RELATED SERIES.
S(x,r) = x + (18 + 18*r^4)*x^5/5! + (14364 + 58968*r^4 + 14364*r^8)*x^9/9! + (70203672 + 671650056*r^4 + 671650056*r^8 + 70203672*r^12)*x^13/13! + (1192064637456 + 20707300240704*r^4 + 47530354598496*r^8 + 20707300240704*r^12 + 1192064637456*r^16)*x^17/17! + (52269828456672288 + 1437626817559769760*r^4 + 5941554215913771840*r^8 + 5941554215913771840*r^12 + 1437626817559769760*r^16 + 52269828456672288*r^20)*x^21/21! + (4930307288899134335424 + 197041019249105562351744*r^4 + 1283341580573615116868160*r^8 + 2308585363008068715943680*r^12 + 1283341580573615116868160*r^16 + 197041019249105562351744*r^20 + 4930307288899134335424*r^24)*x^25/25! + ...
where C(x,r)^4 - S(x,r)^4 = 1.
D(x,r) = 1 + 6*r^4*x^4/4! + (6048*r^4 + 2268*r^8)*x^8/8! + (35126784*r^4 + 56282688*r^8 + 7434504*r^12)*x^12/12! + (679185948672*r^4 + 2514356038656*r^8 + 1409371197696*r^12 + 95227613712*r^16)*x^16/16! + (33022883487154176*r^4 + 220415417637617664*r^8 + 284770675495950336*r^12 + 81696140755536384*r^16 + 3354162536029536*r^20)*x^20/20! + (3393656235362623684608*r^4 + 35701050229143616880640*r^8 + 83079959422282198548480*r^12 + 54913653475645427527680*r^16 + 9583398717725834749440*r^20 + 264444869673131894208*r^24)*x^24/24! +
where D(x,r)^4 - r^4 * C(x,r)^4 = 1 - r^4.

Links

Crossrefs

Cf. A153300 (column 0), A357805 (row sums), A357800 (S(x,r)), A357802 (D(x,r)).
Cf. A357541.

Programs

  • PARI
    {T(n, k) = my(S=x, C=1, D=1); for(i=0, n,
S = intformal( C^3*D^3 +O(x^(4*n+4)));
C = 1 + intformal( S^3*D^3);
D = 1 + r^4*intformal( S^3*C^3); );
(4*n)!*polcoeff( polcoeff(C, 4*n, x), 4*k, r)}
for(n=0, 10, for(k=0, n, print1( T(n, k), ", ")); print(""))
  • PARI
    /* Using Series Reversion (faster) */
{T(n, k) = my(S = serreverse( intformal( 1/((1 + x^4)^3*(1 + r^4*x^4)^3 +O(x^(4*n+4)) )^(1/4) )) );
(4*n)!*polcoeff( polcoeff( (1 + S^4)^(1/4), 4*n, x), 4*k, r)}
for(n=0, 10, for(k=0, n, print1( T(n, k), ", ")); print(""))

Formula

Generating function C(x,r) = Sum_{n>=0} Sum_{k=0..n} T(n,k) * x^(4*n) * r^(4*k) / (4*n)! and related functions S(x,r) and D(x,r) satisfy the following formulas.
For brevity, some formulas here will use S = S(x,r), C = C(x,r), and D = D(x,r).
(1.a) C(x,r)^4 - S(x,r)^4 = 1.
(1.b) D(x,r)^4 - r^4 * S(x,r)^4 = 1.
(1.c) D(x,r)^4 - r^4 * C(x,r)^4 = 1 - r^4.
Integral formulas.
(2.a) S(x,r) = Integral C(x,r)^3 * D(x,r)^3 dx.
(2.b) C(x,r) = 1 + Integral S(x,r)^3 * D(x,r)^3 dx.
(2.c) D(x,r) = 1 + r^4 * Integral S(x,r)^3 * C(x,r)^3 dx.
(2.d) C(x,r)^4 = 1 + 4 * Integral S(x,r)^3 * C(x,r)^3 * D(x,r)^3 dx.
(2.e) D(x,r)^4 = 1 + 4*r^4 * Integral S(x,r)^3 * C(x,r)^3 * D(x,r)^3 dx.
Derivatives.
(3.a) d/dx S(x,r) = C(x,r)^3 * D(x,r)^3.
(3.b) d/dx C(x,r) = S(x,r)^3 * D(x,r)^3.
(3.c) d/dx D(x,r) = r^4 * S(x,r)^3 * C(x,r)^3.
Exponential formulas.
(4.a) C + S = exp( Integral (C^2 - C*S + S^2) * D^3 dx ).
(4.b) D + r*S = exp( r * Integral (D^2 - r*D*S + r^2*S^2) * C^3 dx ).
(4.c) C - S = exp( -Integral (C^2 + C*S + S^2) * D^3 dx ).
(4.d) D - r*S = exp( -r * Integral (D^2 + r*D*S + r^2*S^2) * C^3 dx ).
(5.a) C^2 + S^2 = exp( 2 * Integral S*C * D^3 dx ).
(5.b) D^2 + r^2*S^2 = exp( 2*r^2 * Integral S*D * C^3 dx ).
(5.c) C^2 - S^2 = exp( -2 * Integral S*C * D^3 dx ).
(5.d) D^2 - r^2*S^2 = exp( -2*r^2 * Integral S*D * C^3 dx ).
Hyperbolic functions.
(6.a) C = sqrt(C^2 - S^2) * cosh( Integral (C^2 + S^2) * D^3 dx ).
(6.b) S = sqrt(C^2 - S^2) * sinh( Integral (C^2 + S^2) * D^3 dx ).
(6.c) D = sqrt(D^2 - r^2*S^2) * cosh( r * Integral (D^2 + r^2*S^2) * C^3 dx ).
(6.d) r*S = sqrt(D^2 - r^2*S^2) * sinh( r * Integral (D^2 + r^2*S^2) * C^3 dx ).
(7.a) C^2 = cosh( 2 * Integral S*C * D^3 dx ).
(7.b) S^2 = sinh( 2 * Integral S*C * D^3 dx ).
(7.c) D^2 = cosh( 2*r^2 * Integral S*D * C^3 dx ).
(7.d) r^2*S^2 = sinh( 2*r^2 * Integral S*D * C^3 dx ).
Other formulas.
(8) S(x,r) = Series_Reversion( Integral 1/((1 + x^4)*(1 + r^4*x^4))^(3/4) dx ).
(9.a) T(n,0) = T(n,n) = A153301(n).
(9.b) Sum_{k=0..n} T(n,k) = A357805(n), for n >= 0.
From Paul D. Hanna, Apr 12 2023 (Start):
Let F(x,r) = Integral 1/((1 + x^4)*(1 + r^4*x^4))^(3/4) dx, then
(10.a) S( F(x,r), r) = x,
(10.b) C( F(x,r), r) = (1 + x^4)^(1/4),
(10.c) D( F(x,r), r) = (1 + r^4*x^4)^(1/4). (End)

A357802 Coefficients T(n,k) of x^(4*n)*r^(4*k)/(4*n)! in power series D(x,r) = 1 + r^4 * Integral S(x,r)^3 * C(x,r)^3 dx such that C(x,r)^4 - S(x,r)^4 = 1 and D(x,r)^4 - r^4*S(x,r)^4 = 1, as a triangle read by rows.

Original entry on oeis.org

1, 0, 6, 0, 6048, 2268, 0, 35126784, 56282688, 7434504, 0, 679185948672, 2514356038656, 1409371197696, 95227613712, 0, 33022883487154176, 220415417637617664, 284770675495950336, 81696140755536384, 3354162536029536, 0, 3393656235362623684608, 35701050229143616880640, 83079959422282198548480, 54913653475645427527680, 9583398717725834749440, 264444869673131894208
Offset: 0

Views

Author

Paul D. Hanna, Oct 14 2022

Keywords

Comments

Equals a row reversal of triangle A357801.

Examples

			E.g.f.: D(x,r) = Sum_{n>=0} T(n,k) * x^(4*n) * r^(4*k) / (4*n)! begins:
D(x,r) = 1 + 6*r^4*x^4/4! + (6048*r^4 + 2268*r^8)*x^8/8! + (35126784*r^4 + 56282688*r^8 + 7434504*r^12)*x^12/12! + (679185948672*r^4 + 2514356038656*r^8 + 1409371197696*r^12 + 95227613712*r^16)*x^16/16! + (33022883487154176*r^4 + 220415417637617664*r^8 + 284770675495950336*r^12 + 81696140755536384*r^16 + 3354162536029536*r^20)*x^20/20! + (3393656235362623684608*r^4 + 35701050229143616880640*r^8 + 83079959422282198548480*r^12 + 54913653475645427527680*r^16 + 9583398717725834749440*r^20 + 264444869673131894208*r^24)*x^24/24! +
where D(x,r) = 1 + r^4 * Integral S(x,r)^3 * D(x,r)^3 dx.
TRIANGLE.
This triangle of coefficients T(n,k) of x^(4*n) * r^(4*k) / (4*n)! in D(x,r) for n >= 0, k = 0..n, begins:
n = 0: [1];
n = 1: [0, 6];
n = 2: [0, 6048, 2268];
n = 3: [0, 35126784, 56282688, 7434504];
n = 4: [0, 679185948672, 2514356038656, 1409371197696, 95227613712];
n = 5: [0, 33022883487154176, 220415417637617664, 284770675495950336, 81696140755536384, 3354162536029536];
n = 6: [0, 3393656235362623684608, 35701050229143616880640, 83079959422282198548480, 54913653475645427527680, 9583398717725834749440, 264444869673131894208]; ...
in which the main diagonal equals A153300.
RELATED SERIES.
S(x,r) = x + (18 + 18*r^4)*x^5/5! + (14364 + 58968*r^4 + 14364*r^8)*x^9/9! + (70203672 + 671650056*r^4 + 671650056*r^8 + 70203672*r^12)*x^13/13! + (1192064637456 + 20707300240704*r^4 + 47530354598496*r^8 + 20707300240704*r^12 + 1192064637456*r^16)*x^17/17! + (52269828456672288 + 1437626817559769760*r^4 + 5941554215913771840*r^8 + 5941554215913771840*r^12 + 1437626817559769760*r^16 + 52269828456672288*r^20)*x^21/21! + (4930307288899134335424 + 197041019249105562351744*r^4 + 1283341580573615116868160*r^8 + 2308585363008068715943680*r^12 + 1283341580573615116868160*r^16 + 197041019249105562351744*r^20 + 4930307288899134335424*r^24)*x^25/25! + ...
where D(x,r)^4 - r^4*S(x,r)^4 = 1.
C(x,r) = 1 + 6*x^4/4! + (2268 + 6048*r^4)*x^8/8! + (7434504 + 56282688*r^4 + 35126784*r^8)*x^12/12! + (95227613712 + 1409371197696*r^4 + 2514356038656*r^8 + 679185948672*r^12)*x^16/16! + (3354162536029536 + 81696140755536384*r^4 + 284770675495950336*r^8 + 220415417637617664*r^12 + 33022883487154176*r^16)*x^20/20! + (264444869673131894208 + 9583398717725834749440*r^4 + 54913653475645427527680*r^8 + 83079959422282198548480*r^12 + 35701050229143616880640*r^16 + 3393656235362623684608*r^20)*x^24/24! + ...
where D(x,r)^4 - r^4 * C(x,r)^4 = 1 - r^4.

Links

Crossrefs

Cf. A153300 (diagonal), A357805 (row sums), A357800 (S(x,r)), A357801 (C(x,r)).
Cf. A357542.

Programs

  • PARI
    {T(n, k) = my(S=x, C=1, D=1); for(i=0, n,
S = intformal( C^3*D^3 +O(x^(4*n+4)));
C = 1 + intformal( S^3*D^3);
D = 1 + r^4*intformal( S^3*C^3); );
(4*n)!*polcoeff( polcoeff(D, 4*n, x), 4*k, r)}
for(n=0, 10, for(k=0, n, print1( T(n, k), ", ")); print(""))
  • PARI
    /* Using Series Reversion (faster) */
{T(n, k) = my(S = serreverse( intformal( 1/((1 + x^4)^3*(1 + r^4*x^4)^3 +O(x^(4*n+4)) )^(1/4) )) );
(4*n)!*polcoeff( polcoeff( (1 + r^4*S^4)^(1/4), 4*n, x), 4*k, r)}
for(n=0, 10, for(k=0, n, print1( T(n, k), ", ")); print(""))

Formula

Generating function D(x,r) = Sum_{n>=0} Sum_{k=0..n} T(n,k) * x^(4*n) * r^(4*k) / (4*n)! and related functions S(x,r) and C(x,r) satisfy the following formulas.
For brevity, some formulas here will use S = S(x,r), C = C(x,r), and D = D(x,r).
(1.a) C(x,r)^4 - S(x,r)^4 = 1.
(1.b) D(x,r)^4 - r^4 * S(x,r)^4 = 1.
(1.c) D(x,r)^4 - r^4 * C(x,r)^4 = 1 - r^4.
Integral formulas.
(2.a) S(x,r) = Integral C(x,r)^3 * D(x,r)^3 dx.
(2.b) C(x,r) = 1 + Integral S(x,r)^3 * D(x,r)^3 dx.
(2.c) D(x,r) = 1 + r^4 * Integral S(x,r)^3 * C(x,r)^3 dx.
(2.d) D(x,r)^4 = 1 + r^4 * Integral 4 * S(x,r)^3 * C(x,r)^3 * D(x,r)^3 dx.
Derivatives.
(3.a) d/dx S(x,r) = C(x,r)^3 * D(x,r)^3.
(3.b) d/dx C(x,r) = S(x,r)^3 * D(x,r)^3.
(3.c) d/dx D(x,r) = r^4 * S(x,r)^3 * C(x,r)^3.
Exponential formulas.
(4.a) C + S = exp( Integral (C^2 - C*S + S^2) * D^3 dx ).
(4.b) D + r*S = exp( r * Integral (D^2 - r*D*S + r^2*S^2) * C^3 dx ).
(4.c) C - S = exp( -Integral (C^2 + C*S + S^2) * D^3 dx ).
(4.d) D - r*S = exp( -r * Integral (D^2 + r*D*S + r^2*S^2) * C^3 dx ).
(5.a) C^2 + S^2 = exp( 2 * Integral S*C * D^3 dx ).
(5.b) D^2 + r^2*S^2 = exp( 2*r^2 * Integral S*D * C^3 dx ).
(5.c) C^2 - S^2 = exp( -2 * Integral S*C * D^3 dx ).
(5.d) D^2 - r^2*S^2 = exp( -2*r^2 * Integral S*D * C^3 dx ).
Hyperbolic functions.
(6.a) C = sqrt(C^2 - S^2) * cosh( Integral (C^2 + S^2) * D^3 dx ).
(6.b) S = sqrt(C^2 - S^2) * sinh( Integral (C^2 + S^2) * D^3 dx ).
(6.c) D = sqrt(D^2 - r^2*S^2) * cosh( r * Integral (D^2 + r^2*S^2) * C^3 dx ).
(6.d) r*S = sqrt(D^2 - r^2*S^2) * sinh( r * Integral (D^2 + r^2*S^2) * C^3 dx ).
(7.a) C^2 = cosh( 2 * Integral S*C * D^3 dx ).
(7.b) S^2 = sinh( 2 * Integral S*C * D^3 dx ).
(7.c) D^2 = cosh( 2*r^2 * Integral S*D * C^3 dx ).
(7.d) r^2*S^2 = sinh( 2*r^2 * Integral S*D * C^3 dx ).
Other formulas.
(8) S(x,r) = Series_Reversion( Integral 1/((1 + x^4)*(1 + r^4*x^4))^(3/4) dx ).
(9.a) T(n,0) = T(n,n) = A153301(n).
(9.b) Sum_{k=0..n} T(n,k) = A357805(n), for n >= 0.
From Paul D. Hanna, Apr 12 2023 (Start):
Let F(x,r) = Integral 1/((1 + x^4)*(1 + r^4*x^4))^(3/4) dx, then
(10.a) S( F(x,r), r) = x,
(10.b) C( F(x,r), r) = (1 + x^4)^(1/4),
(10.c) D( F(x,r), r) = (1 + r^4*x^4)^(1/4). (End)

A357804 a(n) = coefficient of x^(4*n+1)/(4*n+1)! in power series S(x) = Series_Reversion( Integral 1/(1 + x^4)^(3/2) dx ).

Original entry on oeis.org

1, 36, 87696, 1483707456, 91329084354816, 14862901723860427776, 5279211177231308343054336, 3600188413031639396548043882496, 4300014195136238449156877005063520256, 8394333803654997846112872487491938363375616, 25378508500092778024069322428694679252236239896576
Offset: 0

Views

Author

Paul D. Hanna, Oct 14 2022

Keywords

Comments

Equals row sums of triangle A357800.

Examples

			E.g.f.: S(x) = x + 36*x^5/5! + 87696*x^9/9! + 1483707456*x^13/13! + 91329084354816*x^17/17! + 14862901723860427776*x^21/21! + 5279211177231308343054336*x^25/25! + ...
such that
S( Integral 1/(1 + x^4)^(3/2) dx ) = x
also
C(x)^4 - S(x)^4 = 1,
where
C(x) = 1 + 6*x^4/4! + 8316*x^8/8! + 98843976*x^12/12! + 4698140798736*x^16/16! + 623259279912288096*x^20/20! + 186936162949832833285056*x^24/24! + ... + A357805(n)*x^(4*n)/(4*n)! + ...

Links

Crossrefs

Cf. A357805 (C(x)), A357800, A153301.

Programs

  • Mathematica
    nmax = 20; Select[CoefficientList[InverseSeries[Series[x*(1/Sqrt[1 + x^4] + Hypergeometric2F1[1/4, 1/2, 5/4, -x^4])/2, {x, 0, 4*nmax + 4}], x], x], #1 != 0 &] * Table[(4*k+1)!, {k, 0, nmax}] (* Vaclav Kotesovec, Apr 09 2025 *)
  • PARI
    /* Using Series Reversion (faster) */
{a(n) = my(S = serreverse( intformal( 1/(1 + x^4 +O(x^(4*n+4)))^(3/2) )) );
(4*n+1)!*polcoeff( S, 4*n+1)}
for(n=0, 10, print1( a(n), ", "))
  • PARI
    {a(n) = my(S=x, C=1); for(i=0, n,
S = intformal( C^6 +O(x^(4*n+4)));
C = 1 + intformal( S^3*C^3 ) );
(4*n)!*polcoeff( C, 4*n)}
for(n=0, 10, print1( a(n), ", "))

Formula

Generating function S(x) = Sum_{n>=0} a(n)*x^(4*n+1)/(4*n+1)! and related function C(x) satisfies the following formulas.
For brevity, some formulas here will use S = S(x) and C = C(x), where C(x) = (1 + S(x)^4)^(1/4) is the e.g.f. of A357805.
(1) C(x)^4 - S(x)^4 = 1.
Integral formulas.
(2.a) S(x) = Integral C(x)^6 dx.
(2.b) C(x) = 1 + Integral S(x)^3 * C(x)^3 dx.
(2.c) S(x)^4 = Integral 4 * S(x)^3 * C(x)^6 dx.
(2.d) C(x)^4 = 1 + Integral 4 * S(x)^3 * C(x)^6 dx.
Derivatives.
(3.a) d/dx S(x) = C(x)^6.
(3.b) d/dx C(x) = S(x)^3 * C(x)^3.
Exponential formulas.
(4.a) C + S = exp( Integral (C^2 - C*S + S^2) * C^3 dx ).
(4.b) C - S = exp( -Integral (C^2 + C*S + S^2) * C^3 dx ).
(5.a) C^2 + S^2 = exp( 2 * Integral S*C^4 dx ).
(5.b) C^2 - S^2 = exp( -2 * Integral S*C^4 dx ).
Hyperbolic functions.
(6.a) C = sqrt(C^2 - S^2) * cosh( Integral (C^2 + S^2) * C^3 dx ).
(6.b) S = sqrt(C^2 - S^2) * sinh( Integral (C^2 + S^2) * C^3 dx ).
(7.a) C^2 = cosh( 2 * Integral S*C^4 dx ).
(7.b) S^2 = sinh( 2 * Integral S*C^4 dx ).
Explicit formulas.
(8.a) S(x) = Series_Reversion( Integral 1/(1 + x^4)^(3/2) dx ).
(8.b) C( Integral 1/(1 + x^4)^(3/2) dx ) = (1 + x^4)^(1/4).
Showing 1-5 of 5 results.

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