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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A277311 G.f. satisfies: A(x - 5*A(x)^2) = x - 4*A(x)^2.

Original entry on oeis.org

1, 1, 12, 200, 4034, 92752, 2353272, 64579809, 1891598860, 58591554652, 1906271367296, 64816527248936, 2294331974613872, 84290267670946720, 3206227129084419920, 126022120854865417140, 5110001578581607976400, 213458728365617240931360, 9175021814527973211291880, 405366362599820848509766760, 18392202994173383123235536800, 856255190568423353781484124240
Offset: 1

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Author

Paul D. Hanna, Oct 12 2016

Keywords

Examples

			G.f.: A(x) = x + x^2 + 12*x^3 + 200*x^4 + 4034*x^5 + 92752*x^6 + 2353272*x^7 + 64579809*x^8 + 1891598860*x^9 + 58591554652*x^10 +...
such that  A(x - 5*A(x)^2) = x - 4*A(x)^2.
A(x)^2 = x^2 + 2*x^3 + 25*x^4 + 424*x^5 + 8612*x^6 + 198372*x^7 + 5028864*x^8 + 137705810*x^9 + 4022209822*x^10 + 124205854376*x^11 + 4028545272136*x^12 + 136566005356212*x^13 + 4820263259998720*x^14 + 176614868022441920*x^15 +...
A(x - 5*A(x)^2) = x - 4*x^2 - 8*x^3 - 100*x^4 - 1696*x^5 - 34448*x^6 - 793488*x^7 - 20115456*x^8 - 550823240*x^9 - 16088839288*x^10 +...
which equals x - 4*A(x)^2.
Series_Reversion(x - 5*A(x)^2) = x + 5*x^2 + 60*x^3 + 1000*x^4 + 20170*x^5 + 463760*x^6 + 11766360*x^7 + 322899045*x^8 + 9457994300*x^9 +...
which equals  5*A(x) - 4*x.
A( 5*A(x) - 4*x ) = x + 6*x^2 + 82*x^3 + 1525*x^4 + 33864*x^5 + 848402*x^6 + 23259832*x^7 + 685028874*x^8 + 21411099560*x^9 + 704295189492*x^10 +24234549363096*x^11 + 868423052983416*x^12 + 32296557071230392*x^13 + 1243216715481216720*x^14 + 49428242214109804120*x^15 +...
which equals  sqrt( A(x) -x ).
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1], F=x); for(i=1, n, A=concat(A, 0); F=x*Ser(A); A[#A] = -polcoeff(subst(F, x, x-5*F^2) + 4*F^2, #A) ); A[n]}
    for(n=1, 30, print1(a(n), ", "))

Formula

G.f. A(x) also satisfies:
(1) A(x) = x + A( 5*A(x) - 4*x )^2.
(2) A(x) = 4*x/5 + 1/5 * Series_Reversion(x - 5*A(x)^2).
(3) R(x) = 5*x/4 - 1/4 * Series_Reversion(x - 4*A(x)^2), where R(A(x)) = x.
(4) R( sqrt( x - R(x) ) ) = 5*x - 4*R(x), where R(A(x)) = x.
(5) A(x) = x + Sum_{n>=1} 5^(n-1) * d^(n-1)/dx^(n-1) A(x)^(2*n) / n!.
a(n) = Sum_{k=0..n-1} A277295(n,k) * 5^k.

A276366 G.f. A(x) satisfies: A(x - A(x)^3) = x + A(x)^2.

Original entry on oeis.org

1, 1, 3, 12, 57, 300, 1697, 10126, 62991, 405247, 2680901, 18160444, 125562250, 883868590, 6321838520, 45869309028, 337167193262, 2508018933431, 18861358215299, 143293615189089, 1098997404472941, 8504070741463729, 66358269984208701, 521923129718567918, 4136089275165532156, 33013640650845937124
Offset: 1

Views

Author

Paul D. Hanna, Sep 01 2016

Keywords

Examples

			G.f.: A(x) = x + x^2 + 3*x^3 + 12*x^4 + 57*x^5 + 300*x^6 + 1697*x^7 + 10126*x^8 + 62991*x^9 + 405247*x^10 + 2680901*x^11 + 18160444*x^12 +...
such that A(x - A(x)^3) = x + A(x)^2.
RELATED SERIES.
A(x - A(x)^3) = x + x^2 + 2*x^3 + 7*x^4 + 30*x^5 + 147*x^6 + 786*x^7 + 4480*x^8 + 26814*x^9 + 166865*x^10 + 1072160*x^11 + 7076724*x^12 +...
which equals x + A(x)^2.
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1], F=x); for(i=1, n, A=concat(A, 0); F=x*Ser(A); A[#A] = -polcoeff(subst(F, x, x-F^3) - F^2, #A) ); A[n]}
    for(n=1, 30, print1(a(n), ", "))

Formula

G.f. A(x) satisfies: A'(x - A(x)^3) = (1 + 2*A'(x)*A(x)) / (1 - 3*A'(x)*A(x)^2).

A277033 G.f. A(x) satisfies: A(x - A(-x)^2) = x + A(x)^2.

Original entry on oeis.org

1, 2, 4, 18, 76, 420, 2248, 14410, 89676, 642764, 4487896, 35282228, 271094936, 2310824808, 19309255952, 177093587874, 1596354765308, 15664040851996, 151403517122328, 1582290415072396, 16319413287176584, 180949924453071544, 1983128441367699632, 23249895784026465044, 269763155110100504568, 3333619355332522429656
Offset: 1

Views

Author

Paul D. Hanna, Oct 09 2016

Keywords

Examples

			G.f.: A(x) = x + 2*x^2 + 4*x^3 + 18*x^4 + 76*x^5 + 420*x^6 + 2248*x^7 + 14410*x^8 + 89676*x^9 + 642764*x^10 +...
such that A(x - A(-x)^2) = x + A(x)^2.
RELATED SERIES.
A(x)^2 = x^2 + 4*x^3 + 12*x^4 + 52*x^5 + 240*x^6 + 1288*x^7 + 7108*x^8 + 43908*x^9 + 275872*x^10 + 1904280*x^11 + 13301112*x^12 +...
sqrt((A(x) - x)/2) = x + x^2 + 4*x^3 + 15*x^4 + 82*x^5 + 420*x^6 + 2742*x^7 + 16767*x^8 + 123294*x^9 + 856042*x^10 + 6906790*x^11 + 53066832*x^12 +...
Series_Reversion( sqrt((A(x) - x)/2) ) = x - x^2 - 2*x^3 - 14*x^5 - 406*x^7 - 16514*x^9 - 872812*x^11 - 56605438*x^13 - 4346269882*x^15 - 386603411414*x^17 - 39262351744912*x^19 - 4504838187841052*x^21 -...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=x,R); for(i=1,n, R = subst(A,x,-x + x*O(x^n)); A = subst(x + A^2,x, serreverse(x - R^2))); polcoeff(A,n)}
    for(n=1,30,print1(a(n),", "))

Formula

G.f. A(x) satisfies: A(-A(-x)) = x.

A277034 G.f. A(x) satisfies: A(x - A(x)^2) = x + A(-x)^2.

Original entry on oeis.org

1, 2, 4, 50, 268, 3780, 28872, 438410, 4087180, 65365260, 697738072, 11624944660, 137432369816, 2371412517480, 30441246407440, 542177876315970, 7460629909188796, 136882304192481020, 2001263659780301080, 37777108180867675020, 583057080531893501960, 11314432259935102732856, 183452721005994056356272
Offset: 1

Views

Author

Paul D. Hanna, Oct 09 2016

Keywords

Examples

			G.f.: A(x) = x + 2*x^2 + 4*x^3 + 50*x^4 + 268*x^5 + 3780*x^6 + 28872*x^7 + 438410*x^8 + 4087180*x^9 + 65365260*x^10 +...
such that A(x - A(x)^2) = x + A(-x)^2.
RELATED SERIES.
A(x)^2 = x^2 + 4*x^3 + 12*x^4 + 116*x^5 + 752*x^6 + 9032*x^7 + 77508*x^8 + 1049348*x^9 + 10608800*x^10 + 155499800*x^11 + 1763239416*x^12 +...
sqrt((A(x) - x)/2) = x + x^2 + 12*x^3 + 55*x^4 + 818*x^5 + 5740*x^6 + 92534*x^7 + 815391*x^8 + 13765254*x^9 + 141099882*x^10 + 2462940118*x^11 +...
Series_Reversion( sqrt((A(x) - x)/2) ) = x - x^2 - 10*x^3 - 294*x^5 - 24998*x^7 - 3158794*x^9 - 506665836*x^11 - 96305392110*x^13 - 20904881285306*x^15 - 5068120123901550*x^17 - 1352637633479800560*x^19 - 393510296576306819932*x^21 -...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=x,R); for(i=1,n, R = subst(A,x,-x + x*O(x^n)); A = subst(x + R^2, x, serreverse(x - A^2 + x*O(x^n)))); polcoeff(A,n)}
    for(n=1,30,print1(a(n),", "))

Formula

G.f. A(x) satisfies: A(-A(-x)) = x.
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