OFFSET
0,3
COMMENTS
Partial sums of Arkons: number of elementary maps with n-1 nodes. The subsequence of primes in the partial sum begins: 2, 3, 7, 17, 163, no more through a(26).
FORMULA
a(n) = SUM[i=0..n] A006343(i) = SUM[i=0..n].
EXAMPLE
a(7) = 1 + 0 + 1 + 1 + 4 + 10 + 34 + 112 = 163 is prime.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 07 2010
STATUS
approved