

A109138


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


0



6, 8, 12, 14, 18, 20, 24, 32, 44, 62, 80, 102, 128, 168, 192, 200, 314, 348, 702
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


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


LINKS

Table of n, a(n) for n=1..19.


EXAMPLE

a(3)=12 because 2^12 + 2 = 4098 and 1+2+3+683+1366+20496 = 4098.


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 *)


CROSSREFS

Cf. A000978.
Sequence in context: A243937 A242058 A322293 * A315858 A123303 A063207
Adjacent sequences: A109135 A109136 A109137 * A109139 A109140 A109141


KEYWORD

nonn,more


AUTHOR

Jason Earls, Aug 18 2005


EXTENSIONS

More terms from David Wasserman, May 28 2008
a(19) from Amiram Eldar, Oct 12 2019


STATUS

approved



