|
%I #24 Apr 17 2022 09:23:42
%S 1,3,9,12,16,18,22,27,29,33,48,54,80,127,133,149,171,335,888,1038,
%T 1137,1435,1465,1647,13921,14256,22467,22872,23514,23709,39564,108708,
%U 108777,109308,230115,837117
%N Numbers k that divide the sum of the digits of (2k)^k.
%C The quotients are 2, 3, 7, 6, 7, 7, 7, 8, 8, 9, 9, 9, 5, 11, 11, 11, 11, 8, 15, 15, 15, 11, 11, 16, 20, 20, 21, 21, 21, 21, 22, 24, 24, 24, 21, 28.
%e 888 is a term because the sum of the digits of (2*888)^888, 13320, is divisible by 888.
%t Do[If[Mod[Plus @@ IntegerDigits[(2*n)^n], n] == 0, Print[n]], {n, 1, 10000}]
%o (Python)
%o A108860_list = [n for n in range(1,1000) if not sum(int(d) for d in str((2*n)**n)) % n] # _Chai Wah Wu_, Mar 15 2018
%Y Cf. A062971.
%K nonn,base,hard,more
%O 1,2
%A _Ryan Propper_, Jul 11 2005
%E a(25)-a(26) from _Harvey P. Dale_, Nov 24 2010
%E a(27)-a(35) from _Lars Blomberg_, Jul 02 2011
%E a(36) from _Kevin P. Thompson_, Apr 15 2022
|
