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.

A380465 G.f. A(x) satisfies A(x) = 1/( 1 - 25*x*A(x)^2 )^(1/5).

Original entry on oeis.org

1, 5, 125, 4250, 166250, 7052500, 315459375, 14648437500, 699404062500, 34120414453125, 1693355782421875, 85222795492187500, 4339218139648437500, 223115431527734375000, 11568972340119140625000, 604249120575386718750000, 31761084429202554931640625, 1678825356066226959228515625
Offset: 0

Views

Author

Seiichi Manyama, Jun 23 2025

Keywords

Crossrefs

Cf. A034688, A078534, A385203, A385204, A385205, A380466, A380471.

Programs

  • PARI
    a(n) = 25^n*binomial(7*n/5+1/5, n)/(7*n+1);

Formula

G.f. A(x) satisfies A(x) = ( 1 + 25*x*A(x)^7 )^(1/5).
a(n) = 25^n * binomial(7*n/5+1/5,n)/(7*n+1).
G.f. A(x) satisfies A(x) = 1/A(-x*A(x)^9).
G.f.: ( (1/x) * Series_Reversion(x/(1+25*x)^(7/5)) )^(1/7).

A380466 G.f. A(x) satisfies A(x) = 1/( 1 - 25*x*A(x)^3 )^(1/5).

Original entry on oeis.org

1, 5, 150, 6250, 301875, 15868125, 881237500, 50865750000, 3021240234375, 183454158593750, 11336659803906250, 710625236343750000, 45075347315400390625, 2887845039367675781250, 186601230428607421875000, 12146710229056792968750000, 795792421294273872070312500
Offset: 0

Views

Author

Seiichi Manyama, Jun 23 2025

Keywords

Crossrefs

Cf. A034688, A078534, A385203, A385204, A385205, A380465, A380471.

Programs

  • PARI
    a(n) = 25^n*binomial(8*n/5+1/5, n)/(8*n+1);

Formula

G.f. A(x) satisfies A(x) = ( 1 + 25*x*A(x)^8 )^(1/5).
a(n) = 25^n * binomial(8*n/5+1/5,n)/(8*n+1).
G.f. A(x) satisfies A(x) = 1/A(-x*A(x)^11).
G.f.: ( (1/x) * Series_Reversion(x/(1+25*x)^(8/5)) )^(1/8).
Showing 1-2 of 2 results.

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

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