A071648 Sum of even decimal digits of n.

0, 2, 0, 4, 0, 6, 0, 8, 0, 0, 0, 2, 0, 4, 0, 6, 0, 8, 0, 2, 2, 4, 2, 6, 2, 8, 2, 10, 2, 0, 0, 2, 0, 4, 0, 6, 0, 8, 0, 4, 4, 6, 4, 8, 4, 10, 4, 12, 4, 0, 0, 2, 0, 4, 0, 6, 0, 8, 0, 6, 6, 8, 6, 10, 6, 12, 6, 14, 6, 0, 0, 2, 0, 4, 0, 6, 0, 8, 0, 8, 8, 10, 8, 12, 8, 14, 8, 16, 8, 0, 0, 2

Offset: 1

Author

Reinhard Zumkeller, May 28 2002

Keywords

• nonn
• base
• easy

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007953, A071649, A071650.

Programs

Mathematica

Array[Total@ Select[IntegerDigits@ #, EvenQ] &, 101] (* Michael De Vlieger, Dec 09 2018 *)

PARI

a(n)=my(d=digits(n)); sum(i=1,#d,if(d[i]%2,,d[i])) \\ Charles R Greathouse IV, Apr 04 2014

PARI

A071648(n)=vecsum(select(d->!bittest(d,0),digits(n))) \\ Nearly twice as fast. - M. F. Hasler, Dec 09 2018

Formula

a(n) = A007953(n) - A071649(n). (Corrected by M. F. Hasler, Dec 09 2018)