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.
%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