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.

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

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%I A177400 #8 Jan 15 2022 15:00:23
%S A177400 1,2,28,2024,635376,820384032,4281625192384,89850821311025280,
%T A177400 7571365534761592422144,2561263066959640762657702400,
%U A177400 3477982739629565890806006777904128
%N A177400 a(n) = binomial(n*2^n, n).
%F A177400 a(n) = [x^n] (1 + x)^(n*2^n).
%F A177400 a(n) = [x^n] Sum_{k=0..n} n^k * log(1 + 2^k*x)^k/k!. - _Paul D. Hanna_, Jul 03 2010
%t A177400 Table[Binomial[n 2^n,n],{n,0,20}] (* _Harvey P. Dale_, Jan 15 2022 *)
%o A177400 (PARI) {a(n)=binomial(n*2^n,n)}
%o A177400 (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
%Y A177400 Cf. A177410, A177411.
%Y A177400 Cf. A136463. - _Paul D. Hanna_, Jul 03 2010
%K A177400 nonn
%O A177400 0,2
%A A177400 _Paul D. Hanna_, Jun 26 2010