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A352168
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a(n) = Sum_{p+q = 2n, p<=q, p,q prime} (p*q mod 2n).
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0
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0, 0, 3, 7, 6, 11, 12, 14, 16, 22, 43, 69, 33, 22, 51, 46, 66, 80, 46, 101, 80, 81, 114, 163, 112, 105, 139, 133, 116, 162, 95, 179, 204, 78, 241, 258, 181, 207, 257, 212, 263, 484, 229, 244, 471, 156, 229, 377, 53, 350, 520, 339, 278, 472, 324, 593, 668, 370, 468, 1092, 244, 275
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OFFSET
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1,3
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LINKS
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FORMULA
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a(n) = Sum_{i=1..n} ( i*(2n-i) mod 2n ) * c(i) * c(2n-i), where c is the prime characteristic (A010051).
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PROG
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(PARI) a(n) = my(s=0); forprime(q=n, 2*n, if (isprime(p=2*n-q), s += (p*q) % (2*n))); s; \\ Michel Marcus, Mar 07 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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