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.

A177400 a(n) = binomial(n*2^n, n).

Original entry on oeis.org

1, 2, 28, 2024, 635376, 820384032, 4281625192384, 89850821311025280, 7571365534761592422144, 2561263066959640762657702400, 3477982739629565890806006777904128
Offset: 0

Views

Author

Paul D. Hanna, Jun 26 2010

Keywords

Crossrefs

Cf. A136463. - Paul D. Hanna, Jul 03 2010

Programs

  • Mathematica
    Table[Binomial[n 2^n,n],{n,0,20}] (* Harvey P. Dale, Jan 15 2022 *)
  • PARI
    {a(n)=binomial(n*2^n,n)}
    
  • PARI
    {a(n)=polcoeff(sum(k=0, n, n^k*log(1+2^k*x +x*O(x^n))^k/k!), n)} \\ Paul D. Hanna, Jul 03 2010

Formula

a(n) = [x^n] (1 + x)^(n*2^n).
a(n) = [x^n] Sum_{k=0..n} n^k * log(1 + 2^k*x)^k/k!. - Paul D. Hanna, Jul 03 2010

A177411 a(n) = binomial((n+1)*2^(n+1), n)/(n+1).

Original entry on oeis.org

1, 4, 92, 10416, 5258872, 11297164096, 100955979001152, 3709635244861142784, 556796318904269731012544, 339945532169833436692992549888, 841788571395046141591475043524725760
Offset: 0

Views

Author

Paul D. Hanna, Jun 26 2010

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Binomial[(n+1)2^(n+1),n]/(n+1),{n,0,20}] (* Harvey P. Dale, Feb 03 2019 *)
  • PARI
    {a(n)=binomial((n+1)*2^(n+1),n)/(n+1)}
    
  • PARI
    {a(n)=polcoeff(sum(k=0, n, 2^k*(n+1)^(k-1)*log(1+2^k*x +x*O(x^n))^k/k!), n)} \\ Paul D. Hanna, Jul 03 2010

Formula

a(n) = [x^n] (1 + x)^((n+1)*2^(n+1))/(n+1).
a(n) = [x^n] Sum_{k=0..n} 2^k*(n+1)^(k-1) * log(1 + 2^k*x)^k/k!. - Paul D. Hanna, Jul 03 2010
Showing 1-2 of 2 results.