1,1

M. F. Hasler, Table of n, a(n) for n = 1..1000

a(n)=A007605(1)+...+A007605(A058049(n))

a(4)=19 because A058049(4)= 5 and sum of digits of 5 first primes, 2+3+5+7+(1+1)=19 is prime.

Corresponding n's: A058049. Primes: A000040, sum of digits of primes: A007605.

Cf. A075544.

Sequence in context: A123364 A025553 A075544 this_sequence A095287 A020608 A075612

Adjacent sequences: A104244 A104245 A104246 this_sequence A104248 A104249 A104250

nonn,base

Zak Seidov (zakseidov(AT)yahoo.com), Feb 26 2005