A118735 Numbers k such that 2^k and 3^k have odd digit sum.

0, 4, 5, 10, 16, 18, 20, 22, 25, 27, 30, 31, 34, 35, 39, 48, 52, 53, 59, 62, 63, 66, 68, 69, 81, 87, 89, 92, 99, 100, 101, 105, 108, 114, 118, 119, 121, 127, 131, 133, 141, 145, 146, 150, 153, 158, 159, 160, 165, 167, 169, 175, 186, 188, 191, 196, 197, 201, 202, 203

Offset: 1

Author

Zak Seidov, May 22 2006

Keywords

• base
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. Intersection of A118731 and A118732.

Programs

Mathematica

Select[Range[0, 206], And @@ ((Mod[ Plus @@ IntegerDigits[ # ], 2] == 1 &) /@ {2^#, 3^#}) &] (* Ray Chandler, Jun 10 2006 *)
odsQ[n_]:=AllTrue[Total[IntegerDigits[#]]&/@{2^n,3^n},OddQ]; Select[ Range[ 0,250],odsQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 05 2021 *)

Extensions

Extended by Ray Chandler, Jun 10 2006