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.

A367028 G.f. satisfies A(x) = 1 + x*A(x) - x^2*A(x)^3.

Original entry on oeis.org

1, 1, 0, -3, -6, 2, 38, 77, -58, -658, -1240, 1562, 13064, 22076, -41710, -279427, -411418, 1114998, 6252048, 7758726, -29876900, -143956676, -143561972, 802102322, 3376515404, 2496314012, -21558225312, -80113377828, -37101814188, 579611761168
Offset: 0

Views

Author

Seiichi Manyama, Nov 02 2023

Keywords

Crossrefs

Cf. A343773, A367029, A367030.
Cf. A000108.

Programs

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

Formula

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

A367029 G.f. satisfies A(x) = 1 + x*A(x) - x^2*A(x)^4.

Original entry on oeis.org

1, 1, 0, -4, -10, 2, 89, 249, -91, -2811, -8071, 4201, 103617, 297201, -200421, -4167581, -11798389, 9803475, 177275251, 492087227, -488311177, -7839760737, -21249466773, 24651743523, 356735365223, 941396264159, -1257287146286, -16589782316762
Offset: 0

Views

Author

Seiichi Manyama, Nov 02 2023

Keywords

Crossrefs

Cf. A343773, A367028, A367030.

Programs

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

Formula

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

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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