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.

Showing 1-10 of 10 results.

A289292 Coefficients in expansion of E_4^(1/2).

Original entry on oeis.org

1, 120, -6120, 737760, -107249640, 17385063120, -3014720249760, 547287510713280, -102701836021530600, 19762301660609250840, -3878226140959368843120, 773209219953012480001440, -156173318001506652330786720, 31888935085481430265623676560
Offset: 0

Views

Author

Seiichi Manyama, Jul 02 2017

Keywords

Crossrefs

E_k^(1/2): A289291 (k=2), this sequence (k=4), A289293 (k=6), A004009 (k=8), A289294 (k=10), A289295 (k=14).
E_4^(k/8): A108091 (k=1), A289307 (k=2), A289308 (k=3), this sequence (k=4), A289309 (k=5), A289318 (k=6), A289319 (k=7).
Cf. A001421, A004009 (E_4), A110163.

Programs

  • Mathematica
    terms = 14;
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E4[x]^(1/2) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 23 2018 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(A110163(n)/2).
a(n) ~ (-1)^(n+1) * c * exp(Pi*sqrt(3)*n) / n^(3/2), where c = 3*Gamma(1/3)^9 / (32*sqrt(2)*Pi^(13/2)) = 0.27646925986847687648926173728588572192308632719... - Vaclav Kotesovec, Jul 02 2017, updated Mar 05 2018
G.f.: 3F2(1/6, 1/2, 5/6; 1, 1; 1728/j) where j is the elliptic modular invariant (A000521). - Seiichi Manyama, Jul 07 2017

A092870 Expansion of Hypergeometric function F(1/12, 5/12; 1; 1728*x) in powers of x.

Original entry on oeis.org

1, 60, 39780, 38454000, 43751038500, 54538294552560, 72081445966966800, 99225259048241726400, 140744828381240373790500, 204278086466816584003782000, 301931182921413583820949947280
Offset: 0

Views

Author

Michael Somos, Mar 08 2004

Keywords

Comments

Self-convolution yields Sum_{k=0..n} a(n-k)*a(k) = A001421(n). - Paul D. Hanna, Jan 25 2011

Crossrefs

Cf. A001421; variants: A184424, A178529, A184891, A184895, A184897. - Paul D. Hanna, Jan 25 2011
Cf. A289307.

Programs

  • Mathematica
    CoefficientList[ Series[ Hypergeometric2F1[ 1/12, 5/12, 1, 1728 x], {x, 0, 10}], x]
  • PARI
    {a(n) = local(an); if( n<1, n==0, an = vector(n+1); an[1] = 1; for(k=1, n, an[k+1] = an[k] * 12 * (12*k - 7) * (12*k - 11) / k^2); an[n+1])}
    
  • PARI
    {a(n)=(12^n/n!^2)*prod(k=0, n-1, (12*k+1)*(12*k+5))} \\ Paul D. Hanna, Jan 25 2011

Formula

G.f.: F(1/12, 5/12; 1; 1728*x). a(n) * n^2 = a(n-1) * 12 * (12*n - 7) * (12*n - 11).
G.f. A(x) = y satisfies 0 = (1728*x^2 - x) * y" + (2592*x - 1) * y' + 60 * y.
a(n) = (12^n/n!^2) * Product_{k=0..n-1} (12k+1)*(12k+5). - Paul D. Hanna, Jan 25 2011
G.f.: A(x) = 1 + 60*x + 39780*x^2 + 38454000*x^3 +... with A(x)^2 = 1 + 120*x + 83160*x^2 + 81681600*x^3 +...+ A184894(n)*x^n +... - Paul D. Hanna, Jan 25 2011
a(n) ~ 1728^n * GAMMA(11/12) * GAMMA(7/12) / (4*Pi^2*n^(3/2)). - Vaclav Kotesovec, Apr 20 2014

A145492 Coefficients of certain power series associated with Atkin polynomials (see Kaneko-Zagier reference for precise definition).

Original entry on oeis.org

1, 450, 394680, 429557700, 522037315800, 678696698599920, 923563866149496000, 1298893924326291064200, 1872892788786285985719000, 2753834730409783196154778800, 4113309164116707723917886096960
Offset: 0

Views

Author

N. J. A. Sloane, Feb 28 2009

Keywords

Crossrefs

Programs

  • PARI
    {a(n) = (8*n+7)*(6*n+1)!/(7*(3*n)!*n!*(n+1)!^2)} \\ Seiichi Manyama, Aug 20 2018

Formula

a(n) = (8*n+7)*(6*n+1)!/(7*(3*n)!*n!*(n+1)!^2). - Seiichi Manyama, Aug 20 2018

Extensions

More terms from Vladeta Jovovic, Feb 28 2009

A145493 Coefficients of certain power series associated with Atkin polynomials (see Kaneko-Zagier reference for precise definition).

Original entry on oeis.org

1, 944, 1054170, 1297994880, 1700941165560, 2326960109485440, 3285120488273369460, 4750462777483659350400, 7000542310802147888540760, 10475220761578770433945887360, 15873347459609903883739895346480, 24308956895577230857746294480107520, 37564030601621705287879755722478648000
Offset: 0

Views

Author

N. J. A. Sloane, Feb 28 2009

Keywords

Crossrefs

Programs

  • PARI
    {a(n) = (41*n+77)/2310*(6*n+6)!/((3*n+3)!*n!*(n+2)!^2)} \\ Seiichi Manyama, Aug 19 2018

Formula

a(n) = (A145492(n+1) - A001421(n+1))/330. - Seiichi Manyama, Aug 18 2018
a(n) = ((41*n+77)/2310) * (6*n+6)!/((3*n+3)!*n!*((n+2)!)^2). - Seiichi Manyama, Aug 19 2018

Extensions

More terms from Seiichi Manyama, Aug 18 2018

A145494 Coefficients of certain power series associated with Atkin polynomials (see Kaneko-Zagier reference for precise definition).

Original entry on oeis.org

1, 1335, 1757970, 2386445040, 3336565609080, 4780478992153590, 6986981484124227300, 10379857332015914783040, 15630336095483779833585240, 23805745537435619756724715080, 36609525021962109091946530420080
Offset: 0

Views

Author

N. J. A. Sloane, Feb 28 2009

Keywords

Crossrefs

Formula

a(n) = (A145493(n+1) - A145492(n+1))/494. - Seiichi Manyama, Aug 18 2018

Extensions

More terms from Vladeta Jovovic, Feb 28 2009

A184896 a(n) = C(2n,n) * (7^n/n!^2) * Product_{k=0..n-1} (7k+1)*(7k+6).

Original entry on oeis.org

1, 84, 45864, 35672000, 32445913500, 32247604076688, 33935228690034672, 37165308416775931392, 41919854708375196052500, 48365506771435816732770000, 56812832722107710740048677120, 67715433011522917282547695380480
Offset: 0

Views

Author

Paul D. Hanna, Jan 25 2011

Keywords

Examples

			G.f.: A(x) = 1 + 84*x + 45864*x^2 + 35672000*x^3 +...
A(x)^(1/2) = 1 + 42*x + 22050*x^2 + 16909900*x^3 +...+ A184895(n)*x^n +...
		

Crossrefs

Programs

  • PARI
    {a(n)=(2*n)!/n!^2*(7^n/n!^2)*prod(k=0,n-1,(7*k+1)*(7*k+6))}

Formula

Self-convolution of A184895, where A184895(n) = (7^n/n!^2) * Product_{k=0..n-1} (14k+1)*(14k+6).
a(n) ~ sin(Pi/7) * 2^(2*n) * 7^(3*n) / (Pi*n)^(3/2). - Vaclav Kotesovec, Oct 23 2020

A184892 a(n) = C(2n,n) * (5^n/n!^2) * Product_{k=0..n-1} (5k+1)*(5k+4).

Original entry on oeis.org

1, 40, 8100, 2310000, 768075000, 278719056000, 107022956040000, 42753018765600000, 17585519046944062500, 7397979398239787500000, 3168258657090171394750000, 1376657183877933677265000000
Offset: 0

Views

Author

Paul D. Hanna, Jan 25 2011

Keywords

Examples

			G.f.: A(x) = 1 + 40*x + 8100*x^2 + 2310000*x^3 +...
A(x)^(1/2) = 1 + 20*x + 3850*x^2 + 1078000*x^3 +...+ A184891(n)*x^n +...
		

Crossrefs

Programs

  • Mathematica
    Table[Binomial[2*n, n] * 5^n / n!^2 * Product[(5*k + 1)*(5*k + 4), {k, 0, n - 1}], {n, 0, 20}] (* Vaclav Kotesovec, Oct 07 2020 *)
  • PARI
    {a(n)=(2*n)!/n!^2*(5^n/n!^2)*prod(k=0,n-1,(5*k+1)*(5*k+4))}

Formula

Self-convolution of A184891, where
. A184891(n) = (5^n/n!^2) * Product_{k=0..n-1} (10k+1)*(10k+4).
a(n) ~ sqrt(5 - sqrt(5)) * 2^(2*n - 3/2) * 5^(3*n) / (Pi^(3/2) * n^(3/2)). - Vaclav Kotesovec, Oct 07 2020

A184898 a(n) = C(2n,n) * (8^n/n!^2) * Product_{k=0..n-1} (8k+1)*(8k+7).

Original entry on oeis.org

1, 112, 90720, 105100800, 142542960000, 211337613527040, 331831362513530880, 542307255307827609600, 912855634598629193472000, 1571864775032876891607040000, 2755743023914838714304931102720
Offset: 0

Views

Author

Paul D. Hanna, Jan 25 2011

Keywords

Examples

			G.f.: A(x) = 1 + 112*x + 90720*x^2 + 105100800*x^3 +...
A(x)^(1/2) = 1 + 56*x + 43792*x^2 + 50098048*x^3 +...+ A184897(n)*x^n +...
		

Crossrefs

Programs

  • PARI
    {a(n)=(2*n)!/n!^2*(8^n/n!^2)*prod(k=0,n-1,(8*k+1)*(8*k+7))}

Formula

Self-convolution of A184897, where A184897(n) = (8^n/n!^2) * Product_{k=0..n-1} (16k+1)*(16k+7).
a(n) ~ sqrt(2-sqrt(2)) * 2^(11*n - 1) / (Pi^(3/2) * n^(3/2)). - Vaclav Kotesovec, Oct 05 2020

A361658 Constant term in the expansion of (1 + x^3 + y^3 + z^3 + 1/(x*y*z))^n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 121, 841, 3361, 10081, 25201, 55441, 194041, 1287001, 7927921, 38438401, 152312161, 516079201, 1627691521, 5745472321, 25999820401, 133086258481, 651284938921, 2860955078521, 11312609403481, 42039298455001, 158864460354601, 658342633033801
Offset: 0

Views

Author

Seiichi Manyama, Mar 19 2023

Keywords

Crossrefs

Programs

  • Mathematica
    Table[n!*Sum[1/(k!^3 * (3*k)! * (n-6*k)!), {k, 0, n/6}], {n, 0, 30}] (* Vaclav Kotesovec, Mar 20 2023 *)
  • PARI
    a(n) = n!*sum(k=0, n\6, 1/(k!^3*(3*k)!*(n-6*k)!));

Formula

a(n) = n! * Sum_{k=0..floor(n/6)} 1/(k!^3 * (3*k)! * (n-6*k)!) = Sum_{k=0..floor(n/6)} binomial(n,6*k) * A001421(k).
From Vaclav Kotesovec, Mar 20 2023: (Start)
Recurrence: (n-4)*(n-2)*n^3*a(n) = (6*n^5 - 45*n^4 + 112*n^3 - 123*n^2 + 68*n - 15)*a(n-1) - 3*(n-1)*(5*n^4 - 40*n^3 + 111*n^2 - 132*n + 59)*a(n-2) + 2*(n-2)*(n-1)*(10*n^3 - 75*n^2 + 181*n - 144)*a(n-3) - (n-3)*(n-2)*(n-1)*(15*n^2 - 90*n + 133)*a(n-4) + 3*(n-4)*(n-3)*(n-2)*(n-1)*(2*n - 7)*a(n-5) + 1727*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*a(n-6).
a(n) ~ (1 + 2*sqrt(3))^(n + 3/2) / (4 * 3^(1/4) * Pi^(3/2) * n^(3/2)). (End)

A145495 Coefficients of certain power series associated with Atkin polynomials (see Kaneko-Zagier reference for precise definition).

Original entry on oeis.org

1, 84, 27720, 13693680, 5354228880, 2489716429200, 1010824870255200, 459492105307435200, 189737418627305920800, 85223723866764909426000, 35532611270849849570013600, 15842376246977818384652245440, 6646596943618421076833646609600, 2948532659526725719238433845966400
Offset: 0

Views

Author

N. J. A. Sloane, Feb 28 2009

Keywords

Examples

			From _Seiichi Manyama_, Aug 19 2018: (Start)
Phi_0(t)/1       = 1 + 120*t +  83160*t^2 + ... (See A001421).
Phi_1(t)/(84*t)  = 1 + 450*t + 394680*t^2 + ... (See A145492).
Phi_2(t)/(27720*t^2)
= (1 + 450*t + 394680*t^2 + ... - (1 + 120*t +  83160*t^2 + ... ))/(330*t)
= 1 + 944*t + 1054170*t^2 + ... (See A145493).
Phi_3(t)/(13693680*t^3)
= (1 + 944*t + 1054170*t^2 + ... - (1 + 450*t + 394680*t^2 + ... ))/(494*t)
= 1 + 1335*t + 1757970*t^2 + ... (See A145494).
Phi_4(t)/(5354228880*t^4)
= (1 + 1335*t + 1757970*t^2 + ... - (1 + 944*t + 1054170*t^2 + ... ))/(391*t)
= 1 + 1800*t + 2783760*t^2 + ... .
Phi_5(t)/(2489716429200*t^5)
= (1 + 1800*t + 2783760*t^2 + ... - (1 + 1335*t + 1757970*t^2 + ... ))/(465*t)
= 1 + 2206*t + 3863952*t^2 + ... .
Phi_6(t)/(1010824870255200*t^6)
= (1 + 2206*t + 3863952*t^2 + ... - (1 + 1800*t + 2783760*t^2 + ... ))/(406*t)
= 1 + 18624/7*t + 36827541/7*t^2 + ... .
Phi_7(t)/(459492105307435200*t^6)
= (1 + 18624/7*t + 36827541/7*t^2 + ... - (1 + 2206*t + 3863952*t^2 + ... ))/((3182/7)*t)
= 1 + (6147/2)*t + 6715687*t^2 + ... . (End)
		

Crossrefs

Formula

From Seiichi Manyama, Aug 19 2018: (Start)
a(n) = (6*n+1)!/((n-1)!*(2*n)!*(3*n)!*(6*n+(-1)^n)) for n > 0.
a(n) = 12*(6*n-6+(-1)^(n-1))*(6*n+(-1)^(n-1))*a(n-1)/((n-1)*n) for n > 1. (End)

Extensions

More terms from Seiichi Manyama, Aug 19 2018
Showing 1-10 of 10 results.