OFFSET
0,2
COMMENTS
Partial sums of number of Giuga sequences of length n. The only known primes in this partial sum are 3 and 23.
FORMULA
a(n) = SUM[i=0..n] A029876(i) = SUM[i=0..n] {numbers i such that p divides i/p - 1 for every prime divisor p of i}.
EXAMPLE
a(4) = 1 + 2 + 3 + 17 + 27 = 50.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Apr 17 2010
STATUS
approved