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A108130
Partial sums of A108129.
0
2, 3, 5, 6, 7, 9, 12, 13, 15, 16, 17, 21, 24, 25, 29, 30, 32, 34, 35, 38, 40, 47, 48, 52, 53, 54, 56, 57, 58, 70, 73, 75, 79, 84, 85, 87, 94, 95, 97, 98, 101, 103, 108, 109, 113, 114, 117, 119, 120, 121, 131, 134, 136, 146, 155, 157, 165, 166, 167, 179, 180
OFFSET
1,1
PROG
(PARI) f(n) = my(k=2*n-1, m=1); while(!isprime(k*2^m-1), m++); m; \\ A108129
a(n) = sum(k=1, n, a(k));
CROSSREFS
Cf. A108129.
Sequence in context: A082984 A085717 A253083 * A195060 A153763 A345982
KEYWORD
nonn
AUTHOR
Jorge Coveiro, Jun 04 2005
EXTENSIONS
a(14) and following corrected by Georg Fischer, Dec 26 2022
Offset 1 from Michel Marcus, Dec 26 2022
STATUS
approved