A119496 Numbers n such that 2^n, 3^n, 5^n and 7^n have even digit sum.
15, 64, 83, 90, 106, 107, 120, 122, 135, 168, 173, 180, 181, 185, 193, 198, 222, 229, 239, 242, 289, 299, 347, 356, 364, 369, 407, 424, 447, 458, 462, 470, 479, 481, 503, 542, 552, 568, 580, 583, 607, 612, 648, 657, 676, 683, 684, 688, 742, 758, 787
Offset: 1
Examples
{2^15,3^15,5^15,7^15}={32768,14348907,30517578125,4747561509943} with even digit sum {26,36,44,64}.
Programs
-
Mathematica
Select[Range[800],AllTrue[Total/@(IntegerDigits/@({2,3,5,7}^#)),EvenQ]&] (* Harvey P. Dale, Oct 13 2022 *) -
PARI
isok(n) = !(sumdigits(2^n) % 2) && !(sumdigits(3^n) % 2) && !(sumdigits(5^n) % 2) && !(sumdigits(7^n) % 2); \\ Michel Marcus, Oct 10 2013