A276496 a(n) is the least positive k such that A276495(n) + 2^k is prime.

1, 2, 5, 6, 10, 11, 60, 75, 1404, 1974, 16389, 37105

Offset: 1

Author

Arkadiusz Wesolowski, Sep 05 2016

Keywords

• nonn
• hard
• more

Comments

If A276495(13) = 453143, then a(13) > 10^5.

Crossrefs

Cf. A067760, A276495.

Programs

Magma

lst:=[]; c:=0; for n in [1..31951 by 2] do m:=-1; repeat m+:=1; a:=n-2^m; until a lt 1 or IsPrime(a); if a lt 1 then k:=0; repeat k+:=1; b:=n+2^k; until IsPrime(b); if k gt c then Append(~lst, k); c:=k; end if; end if; end for; lst;

Extensions

Typo in name corrected by Rémy Sigrist, Sep 12 2016