A135285 Sum of staircase twin primes according to the rule: top * bottom - next top.

10, 24, 126, 294, 858, 1704, 3528, 5082, 10296, 11526, 18894, 22320, 32208, 36666, 38976, 51744, 57330, 72618, 79212, 96996, 120684, 175968, 186162, 212922, 271914, 324300, 359382, 381282, 411504, 434790, 655278, 674856, 684726, 735282, 776904

Offset: 1

Author

Cino Hilliard, Dec 03 2007

Keywords

• nonn

Comments

While there is multiplication and subtraction in the generation of this sequence, it is still called a sum because the arithmetic processes -,*,/ are derived from addition.

Programs

PARI

g(n) = for(x=1,n,y=twinu(x) * twinl(x) - twinl(x+1);print1(y",")) twinl(n) = / *The n-th lower twin prime. */ { local(c,x); c=0; x=1; while(c
				

Formula

We list the twin primes in staircase fashion as in A135283. Then a(n) = tl(n) * tu(n) + (-tl(n+1)).

a(n) = A037074(n) -A001359(n+1). - R. J. Mathar, Sep 10 2016