1,3

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

a(21)=14 since 21 and 20 are written in base 3 as 210 and 202 and so their tersum is 112 in base 3, i.e. 9+3+2=14.

Cf. A004482, A004488, A004489, A038712.

Sequence in context: A063005 A145577 A144478 * A175294 A196615 A305200

Adjacent sequences: A059246 A059247 A059248 * A059250 A059251 A059252

nonn

Henry Bottomley, Jan 22 2001

approved