A154387 Composite numbers with even sum of digits.

4, 6, 8, 15, 20, 22, 24, 26, 28, 33, 35, 39, 40, 42, 44, 46, 48, 51, 55, 57, 60, 62, 64, 66, 68, 75, 77, 80, 82, 84, 86, 88, 91, 93, 95, 99, 105, 110, 112, 114, 116, 118, 121, 123, 125, 129, 130, 132, 134, 136, 138, 141, 143, 145, 147, 150, 152, 154, 156, 158, 161

Offset: 1

Author

Juri-Stepan Gerasimov, Jan 08 2009

Keywords

• nonn
• base

Examples

			15 is composite and 1 + 5 = 6 (an even number), so 15 is a term;
20 is composite and 2 + 0 = 2 (an even number), so 20 is a term.
		

Links

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

Crossrefs

Intersection of A002808 and A054683.

Programs

Maple

sd := proc (n) options operator, arrow: add(convert(n, base, 10)[j], j = 1 .. nops(convert(n, base, 10))) end proc: a := proc (n) if isprime(n) = false and `mod`(sd(n), 2) = 0 then n else end if end proc: seq(a(n), n = 2 .. 180); # Emeric Deutsch, Jan 17 2009

Mathematica

Select[Range[200],CompositeQ[#]&&EvenQ[Total[IntegerDigits[#]]]&] (* Harvey P. Dale, Aug 25 2016 *)

Extensions

Replaced 45 by 46 - R. J. Mathar, Jan 12 2009

More terms from Emeric Deutsch, Jan 17 2009