OFFSET
0,3
COMMENTS
Partial sums of number of increasing mobiles with n elements. In an increasing rooted tree, nodes are numbered and numbers increase as you move away from root. The subsequence of primes in this partial sum begins: 2, 11, 47, 272263.
LINKS
Robert Israel, Table of n, a(n) for n = 0..416
FORMULA
a(n) = SUM[i=o..n] A029768(i).
EXAMPLE
a(x) = 0 + 1 + 1 + 2 + 7 + 36 + 245 + 2076 + 21059 + 248836 = 272263 is prime.
MAPLE
S:= rhs(dsolve({diff(a(x), x) = log(1/(1-a(x)))+1, a(0)=0}, a(x), series, order=31)):
L:= [seq(coeff(S, x, j)*j!, j=0..30)]:
ListTools:-PartialSums(L); # Robert Israel, Dec 21 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Mar 24 2010
STATUS
approved