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A015889
Numbers k that divide 4^k + 4.
11
1, 2, 4, 10, 20, 52, 130, 370, 1066, 1090, 2626, 4580, 7540, 9140, 21268, 21682, 24634, 26596, 29380, 38740, 40330, 65026, 146810, 152164, 154180, 159172, 211492, 271426, 290116, 330706, 432730, 567988, 575956, 710788, 782090
OFFSET
1,2
LINKS
MATHEMATICA
Select[Range[800000], Divisible[4^#+4, #]&] (* Harvey P. Dale, Jun 06 2012 *)
KEYWORD
nonn
EXTENSIONS
Corrected (a(2) = 2 inserted) by Harvey P. Dale, Jun 06 2012
STATUS
approved