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 A260756 #9 Jul 30 2015 23:35:47 %S A260756 1,2,10,44739260, %T A260756 28948022309329048855892746252171976963317496166410141009864396001978371888518 %N A260756 G.f.: exp( Sum_{n>=1} 2^(n^n) * x^n/n ). %C A260756 Does the g.f. describe an integer sequence? %C A260756 The number of digits in the terms begin: [1, 1, 2, 8, 77, 941, 14045, 247911, ...]. %e A260756 G.f.: A(x) = 1 + 2*x + 10*x^2 + 44739260*x^3 +... %e A260756 where %e A260756 log(A(x)) = 2^1*x + 2^4*x^2/2 + 2^27*x^3/3 + 2^256*x^4/4 + 2^3125*x^5/5 + 2^46656*x^6/6 + 2^823543*x^7/7 + 2^16777216*x^8/8 +...+ 2^(n^n)*x^n/n +... %o A260756 (PARI) {a(n)=polcoeff(exp(sum(m=1, n+1, 2^(m^m)*x^m/m)+x*O(x^n)), n)} %o A260756 for(n=0,7,print1(a(n),", ")) %Y A260756 Cf. A155200, A158110. %K A260756 nonn %O A260756 0,2 %A A260756 _Paul D. Hanna_, Jul 30 2015