A118733 -id:A118733 - cp's OEIS frontend

A118734 Numbers k such that 2^k and 3^k have even digit sum.

6, 15, 33, 37, 42, 43, 44, 46, 47, 50, 54, 55, 57, 58, 64, 67, 70, 71, 77, 82, 83, 84, 85, 90, 95, 102, 106, 107, 112, 116, 120, 122, 126, 129, 135, 136, 138, 140, 142, 149, 154, 161, 168, 170, 173, 176, 178, 179, 180, 181, 185, 193, 195, 198, 200, 207, 209, 210, 217

Offset: 1

Zak Seidov, May 22 2006

Robert Israel, Table of n, a(n) for n = 1..10000

Cf. Intersection of A118730 and A118733.

filter:= proc(n) convert(convert(2^n,base,10),`+`)::even and convert(convert(3^n,base,10),`+`)::even end proc:
select(filter, [$1..1000]); # Robert Israel, Apr 12 2021

Select[Range[220], And @@ ((Mod[ Plus @@ IntegerDigits[ # ], 2] == 0 &) /@ {2^#, 3^#}) &] (* Ray Chandler, Jun 10 2006 *)

Extended by Ray Chandler, Jun 10 2006

A118730 Numbers k such that 2^k has even digit sum.

Original entry on oeis.org

1, 2, 3, 6, 9, 11, 13, 14, 15, 17, 21, 26, 32, 33, 36, 37, 41, 42, 43, 44, 45, 46, 47, 50, 51, 54, 55, 57, 58, 60, 61, 64, 65, 67, 70, 71, 73, 74, 76, 77, 78, 79, 80, 82, 83, 84, 85, 86, 90, 91, 95, 98, 102, 103, 106, 107, 112, 113, 115, 116, 117, 120, 122, 123, 124, 126

Offset: 1

Zak Seidov, May 22 2006

Robert Israel, Table of n, a(n) for n = 1..10000

Cf. A118733, A118734.

filter:= proc(n) convert(convert(2^n,base,10),`+`)::even end proc:
select(filter, [$1..1000]); # Robert Israel, Apr 12 2021

Select[Range[126], Mod[ Plus @@ IntegerDigits[2^# ], 2] == 0 &] (* Ray Chandler, Jun 10 2006 *)

cp's OEIS Frontend

A118734 Numbers k such that 2^k and 3^k have even digit sum.

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