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 1-6 of 6 results.

A364629 G.f. satisfies A(x) = (1+x*A(x)^3)/(1-x)^2.

Original entry on oeis.org

1, 3, 14, 94, 735, 6239, 55888, 520028, 4977321, 48689260, 484623552, 4892304686, 49971163021, 515496741918, 5363023614620, 56204877993184, 592811175777029, 6287909183751105, 67029933733468729, 717749621979800340, 7716543390041275964
Offset: 0

Views

Author

Seiichi Manyama, Jul 30 2023

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n, binomial(n+5*k+1, 6*k+1)*binomial(3*k, k)/(2*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(n+5*k+1,6*k+1) * binomial(3*k,k) / (2*k+1).

A162476 Expansion of (1/(1-x))*c(x/(1-x)^4), c(x) the g.f. of A000108.

Original entry on oeis.org

1, 2, 8, 39, 205, 1136, 6548, 38882, 236260, 1462131, 9184413, 58408588, 375330536, 2433325315, 15896742423, 104546968252, 691608993478, 4599024778431, 30724413312953, 206114347293697, 1387917616331135, 9377747277136328
Offset: 0

Views

Author

Paul Barry, Jul 04 2009

Keywords

Comments

Partial sums are A162477. Partial sums of A162475.

Formula

G.f.: 1/(1-x-x/((1-x)^3-x/(1-x-x/((1-x)^3-x/(1-x-x/((1-x)^3-x/(1-... (continued fraction);
a(n) = Sum_{k=0..n} C(n+3k,n-k)*A000108(k).
(n+1)*(2*n-3)*a(n) -(4*n-3)*(4*n-5)*a(n-1) +3*(4*n^2-14*n+11)*a(n-2) +(-8*n^2+40*n-27)*a(n-3) +(2*n-1)*(n-6)*a(n-4) = 0. - R. J. Mathar, Nov 15 2011

A363816 G.f. satisfies A(x) = (1 + x/A(x))/(1 - x)^2.

Original entry on oeis.org

1, 3, 2, 8, -9, 62, -230, 1054, -4753, 22208, -105419, 508396, -2482284, 12248430, -60980860, 305955372, -1545397447, 7852100312, -40105277621, 205798130624, -1060467961487, 5485199090834, -28469067353663, 148220323891484, -773892318396664, 4051261817405034
Offset: 0

Views

Author

Seiichi Manyama, Oct 18 2023

Keywords

Crossrefs

Partial sums of A366356.

Programs

  • Mathematica
    A363816[n_]:=(-1)^(n-1)Sum[Binomial[2k-1,k]Binomial[2(k-1),n-k]/(2k-1),{k,0,n}];Array[A363816,30,0] (* Paolo Xausa, Oct 20 2023 *)
  • PARI
    a(n) = (-1)^(n-1)*sum(k=0, n, binomial(2*k-1, k)*binomial(2*(k-1), n-k)/(2*k-1));

Formula

G.f.: A(x) = -2*x / (1-sqrt(1+4*x*(1-x)^2)).
a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(2*k-1,k) * binomial(2*(k-1),n-k)/(2*k-1).

A364630 G.f. satisfies A(x) = (1+x*A(x)^4)/(1-x)^2.

Original entry on oeis.org

1, 3, 17, 153, 1621, 18732, 229103, 2915498, 38204497, 512027945, 6985933889, 96705749625, 1354868839933, 19175008086962, 273731258980839, 3936883123412972, 56991044183321197, 829750943505927435, 12142121554514962205, 178488780583916045949
Offset: 0

Views

Author

Seiichi Manyama, Jul 30 2023

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n, binomial(n+7*k+1, 8*k+1)*binomial(4*k, k)/(3*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(n+7*k+1,8*k+1) * binomial(4*k,k) / (3*k+1).

A363818 G.f. satisfies A(x) = (1 + x/A(x)^2)/(1 - x)^2.

Original entry on oeis.org

1, 3, -1, 24, -125, 924, -6895, 54181, -438737, 3639655, -30769033, 264122781, -2296010693, 20171456222, -178818115155, 1597550237324, -14369097515939, 130010781029079, -1182520161325459, 10806114831458755, -99163805247182631, 913441732959868748
Offset: 0

Views

Author

Seiichi Manyama, Oct 18 2023

Keywords

Crossrefs

Programs

  • PARI
    a(n) = (-1)^(n-1)*sum(k=0, n, binomial(3*k-1, k)*binomial(2*(2*k-1), n-k)/(3*k-1));

Formula

a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(3*k-1,k) * binomial(2*(2*k-1),n-k)/(3*k-1).

A376159 G.f. satisfies A(x) = 1 / ((1-x)^3 - x*A(x)).

Original entry on oeis.org

1, 4, 17, 90, 539, 3451, 23100, 159720, 1131905, 8178326, 60019533, 446166771, 3352530190, 25422458170, 194302002463, 1495223230621, 11575504625874, 90090318248607, 704480581789900, 5532228951823605, 43610427926723780, 344972119634359080, 2737451123900901555
Offset: 0

Views

Author

Seiichi Manyama, Sep 12 2024

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(2/((1-x)^3+sqrt((1-x)^6-4*x)))
    
  • PARI
    a(n) = sum(k=0, n, binomial(n+5*k+2, n-k)*binomial(2*k, k)/(k+1));

Formula

G.f.: 2 / ((1-x)^3 + sqrt((1-x)^6 - 4*x)).
a(n) = Sum_{k=0..n} binomial(n+5*k+2,n-k) * binomial(2*k,k)/(k+1).
Showing 1-6 of 6 results.