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 1-2 of 2 results.

A379037 G.f. A(x) satisfies A(x) = ( (1 + x) * (1 + x*A(x)^(3/2)) )^2.

Original entry on oeis.org

1, 4, 18, 106, 689, 4782, 34707, 260190, 1999168, 15660176, 124596498, 1004110948, 8179379807, 67239070868, 557098881919, 4647368670950, 39001655222787, 329048378867468, 2789241880512898, 23743798316713368, 202894843070927859, 1739775692700850554
Offset: 0

Views

Author

Seiichi Manyama, Dec 14 2024

Keywords

Crossrefs

Programs

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

Formula

G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A364336.
a(n) = 2 * Sum_{k=0..n} binomial(3*k+2,k) * binomial(3*k+2,n-k)/(3*k+2).

A379038 G.f. A(x) satisfies A(x) = ( (1 + x) * (1 + x*A(x)^(4/3)) )^3.

Original entry on oeis.org

1, 6, 39, 320, 2907, 28152, 284907, 2977116, 31875708, 347884085, 3855802689, 43283239650, 491083601338, 5622489637407, 64877058557079, 753705528179424, 8808460811302728, 103487549564845200, 1221565052783161763, 14480208437556590346, 172299129911222223324
Offset: 0

Views

Author

Seiichi Manyama, Dec 14 2024

Keywords

Crossrefs

Programs

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

Formula

G.f.: A(x) = B(x)^3 where B(x) is the g.f. of A364337.
a(n) = 3 * Sum_{k=0..n} binomial(4*k+3,k) * binomial(4*k+3,n-k)/(4*k+3).
Showing 1-2 of 2 results.