A260756 G.f.: exp( Sum_{n>=1} 2^(n^n) * x^n/n ).

1, 2, 10, 44739260, 28948022309329048855892746252171976963317496166410141009864396001978371888518

Offset

0,2

Comments

Does the g.f. describe an integer sequence?

The number of digits in the terms begin: [1, 1, 2, 8, 77, 941, 14045, 247911, ...].

Links

Table of n, a(n) for n=0..4.

Example

G.f.: A(x) = 1 + 2*x + 10*x^2 + 44739260*x^3 +...
where
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 +...

Prog

(PARI) {a(n)=polcoeff(exp(sum(m=1, n+1, 2^(m^m)*x^m/m)+x*O(x^n)), n)}
for(n=0, 7, print1(a(n), ", "))

Crossrefs

Cf. A155200, A158110.

Sequence in context: A057095 A119189 A309862 * A252707 A288848 A374945

Adjacent sequences: A260753 A260754 A260755 * A260757 A260758 A260759

Keyword

nonn

Author

Paul D. Hanna, Jul 30 2015

Status

approved