A191001 Indices k where A191620(k) = A191751(k).
1, 2, 4, 5, 9, 10, 18, 26, 34, 38, 45, 50, 57, 88, 108, 115, 161, 208, 224, 225, 238, 240, 264, 354, 597, 634, 984, 1008, 1080, 1468
Offset: 1
Examples
1 is a term because A191620(1) = A191751(1) = 0; 2 is a term because A191620(2) = A191751(2) = 1.
Programs
-
Maple
A191751 := proc(n) local k; for k from 0 do if isprime((2^n-1)*2^n-k) then return k: end if : end do: end proc: A191620 := proc(n) local k: for k from 0 do if isprime((2^n-k)*2^n-1) then return k: end if: end do: end proc: for n from 1 do if A191751(n) = A191620(n) then printf("%d,\n",n); end if; end do: # R. J. Mathar, Jun 25 2011
Extensions
a(25)-a(30) from Jinyuan Wang, May 15 2020