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A156778 n*A007504(n)/2 = n*(sum of first n primes)/2 1
0, 1, 5, 15, 34, 70, 123, 203, 308, 450, 645, 880, 1182, 1547, 1967, 2460, 3048, 3740, 4509, 5396, 6390, 7476, 8701, 10051, 11556, 13250, 15093, 17064, 19194, 21460, 23895, 26660, 29616, 32802, 36159, 39830, 43686, 47804, 52193, 56823, 61740 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
For n>0, the sum of the first n primes, A007504(n), has the opposite parity of n (since both increase by an odd amount, and A007504(n)=2 for n=1.
LINKS
FORMULA
a(n) = A156780( prime(n))/2, where prime(n) = A000040(n) is the n-th prime.
PROG
(PARI) vector(80, n, sum(i=1, n, prime(i))*n)/2
CROSSREFS
Cf. A156780.
Sequence in context: A084288 A083049 A015627 * A346752 A292955 A295005
KEYWORD
nonn
AUTHOR
M. F. Hasler, Feb 21 2009
STATUS
approved

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Last modified July 25 08:50 EDT 2024. Contains 374587 sequences. (Running on oeis4.)