A152531 a(n) = (p(n)*p(n+2) - p(n+1))/2, where p(n) is the n-th odd prime.

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

Author

Omar E. Pol, Dec 06 2008

Keywords

• easy
• nonn

Comments

This is A111071 without its first term. - R. J. Mathar, Jul 27 2015

Crossrefs

Cf. A065091, A111071, A152527, A152528, A152529, A152530, A152532.

Programs

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 *)

Formula

a(n) = A152530(n+1)/2.