1,2

Table of n, a(n) for n=1..72.

a(n) = 1 (if n = 1); a(n) = n + a("occurrence of digit 1 in n(binary)") else;

a(13)=19 because 13 = (1101) -> (1+1+0+1 = 11) -> (1+1 = 10) -> (1+0 = 1) = 1 and 1101+11+10+1(binary) = 19(decimal).

Cf. A078627.

Sequence in context: A082284 A241474 A063520 * A059770 A019690 A010620

Adjacent sequences: A078674 A078675 A078676 * A078678 A078679 A078680

base,easy,nonn

Frank Schwellinger (nummer_eins(AT)web.de), Dec 17 2002

approved