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A152117
a(n) = n*(n-th prime) + (n+1)*((n+1)-th prime).
9
8, 21, 43, 83, 133, 197, 271, 359, 497, 631, 785, 977, 1135, 1307, 1553, 1851, 2101, 2371, 2693, 2953, 3271, 3647, 4045, 4561, 5051, 5407, 5777, 6157, 6551, 7327, 8129, 8713, 9247, 9941, 10651, 11245, 12003, 12707, 13433, 14259, 14941, 15815, 16705
OFFSET
1,1
COMMENTS
a(n) = A033286(n) + A033286(n+1).
LINKS
EXAMPLE
5*(fifth prime) + 6*(sixth prime) = 5*11 + 6*13 = 55 + 78 = 133.
MATHEMATICA
Total/@Partition[Times@@@Table[{n, Prime[n]}, {n, 50}], 2, 1] (* Harvey P. Dale, Aug 13 2019 *)
PROG
(Magma) [ n*NthPrime(n)+(n+1)*NthPrime(n+1): n in [1..43] ];
(PARI) a(n) = n*prime(n) + (n+1)*prime(n+1); \\ Michel Marcus, Feb 05 2016
CROSSREFS
Cf. A000040 (prime numbers), A033286 (n*(n-th prime)), A033287 (first differences of A033286), A119487 (primes in this sequence).
Sequence in context: A190456 A188026 A180672 * A075629 A273602 A258448
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Dec 10 2008
STATUS
approved