A139368 a(n) = A024912(n) - A102342(n).

1, 2, 1, 2, 1, 1, 3, 3, 5, 4, 5, 5, 3, 2, 1, 1, 2, 7, 8, 7, 7, 4, 6, 6, 3, 5, 6, 6, 6, 8, 6, 8, 4, 6, 4, 9, 9, 9, 10, 11, 12, 10, 11, 10, 12, 16, 9, 9, 9, 5, 8, 7, 5, 7, 8, 13, 11, 6, 7, 5, 1, 1, 2, 10, 11, 15, 15, 14, 12, 10, 12, 9, 9, 14, 18, 13, 14, 13, 14, 14, 12, 8, 8, 8, 7, 8, 4, 6, 7, 11, 10

Offset: 1

Author

Juri-Stepan Gerasimov, Jun 09 2008

Keywords

• sign

Comments

A139368(219) = -4.

Links

• Index entries for prime races

Programs

Maple

From R. J. Mathar, Apr 25 2010: (Start)
A102342 := proc(n) option remember; if n = 1 then 0; else for a from procname(n-1)+1 do if isprime(10*a+7) then return a; end if; end do: end if; end proc:
A024912 := proc(n) option remember; if n = 1 then 1; else for a from procname(n-1)+1 do if isprime(10*a+1) then return a; end if; end do: end if; end proc:
A139368 := proc(n) A024912(n)-A102342(n) ; end proc: seq(A139368(n),n=1..120) ; (End)

Extensions

More terms from R. J. Mathar, Apr 25 2010