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A152531
a(n) = (p(n)*p(n+2) - p(n+1))/2, where p(n) is the n-th odd prime.
6
8, 24, 40, 87, 115, 186, 264, 342, 521, 617, 775, 942, 1116, 1360, 1587, 1946, 2132, 2410, 2768, 2990, 3474, 3981, 4446, 4945, 5352, 5560, 5991, 6865, 7338, 8634, 9036, 10137, 10420, 11621, 12228, 13028, 14016, 14860, 15567, 17004
OFFSET
1,1
COMMENTS
This is A111071 without its first term. - R. J. Mathar, Jul 27 2015
FORMULA
a(n) = A152530(n+1)/2.
MAPLE
A152531 := proc(n)
j := n+1 ;
ithprime(j)*ithprime(j+2)-ithprime(j+1) ;
%/2 ;
end proc: # R. J. Mathar, Jul 28 2015
MATHEMATICA
(First[#]*Last[#]-#[[2]])/2&/@Partition[Prime[Range[2, 50]], 3, 1] (* Harvey P. Dale, Oct 09 2014 *)
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Dec 06 2008
STATUS
approved