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

1,2

Comments

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

Links

Table of n, a(n) for n=1..12.

Prog

(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;

Crossrefs

Cf. A067760, A276495.

Sequence in context: A238096 A064572 A032399 * A007969 A187902 A187231

Adjacent sequences: A276493 A276494 A276495 * A276497 A276498 A276499

Keyword

nonn,hard,more

Author

Arkadiusz Wesolowski, Sep 05 2016

Extensions

Typo in name corrected by Rémy Sigrist, Sep 12 2016

Status

approved