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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 Table of n, a(n) for n=0..40. 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 Adjacent sequences: A156775 A156776 A156777 * A156779 A156780 A156781 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.)