A109138 Numbers n such that 2^n + 2 is an admirable number (A111592).

6, 8, 12, 14, 18, 20, 24, 32, 44, 62, 80, 102, 128, 168, 192, 200, 314, 348, 702

Offset: 1

Author

Jason Earls, Aug 18 2005

Keywords

• nonn
• more

Comments

For k > 1, A000978(k)+1 is a member. Are there any others? - David Wasserman, May 28 2008

No more terms below 1064. - Amiram Eldar, Oct 12 2019

Examples

			a(3)=12 because 2^12 + 2 = 4098 and 1+2+3+683+1366+2049-6 = 4098.
		

Crossrefs

Cf. A000978.

Programs

Mathematica

fQ[n_] := Block[{d = Most[ Divisors[n]], k = 1}, l = Length[d]; s = Plus @@ d; While[k < l && s - 2d[[k]] > n, k++ ]; If[k > l || s != n + 2d[[k]], False, True]]; Do[ If[ fQ[2^n + 2], Print[n]], {n, 200}] (* Robert G. Wilson v, Aug 30 2005 *)

Extensions

More terms from David Wasserman, May 28 2008

a(19) from Amiram Eldar, Oct 12 2019