A215092 a(n) = Sum_{i=0..m} d(i)*3^i, where Sum_{i=0..m} d(i)*6^i is the base-6 representation of n.

1, 2, 3, 4, 5, 3, 4, 5, 6, 7, 8, 6, 7, 8, 9, 10, 11, 9, 10, 11, 12, 13, 14, 12, 13, 14, 15, 16, 17, 15, 16, 17, 18, 19, 20, 9, 10, 11, 12, 13, 14, 12, 13, 14, 15, 16, 17, 15, 16, 17, 18, 19, 20, 18, 19, 20, 21, 22, 23, 21, 22, 23, 24, 25, 26, 24, 25, 26, 27, 28, 29, 18

Offset: 1

Author

Clark Kimberling, Aug 13 2012

Keywords

• nonn
• base
• easy

Links

• Clark Kimberling, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A037454.

Programs

Magma

[n eq 1 select 1 else n mod 6 eq 0 select 3*Self(n div 6) else Self(n-1)+1: n in [1..72]]; // Bruno Berselli, Jan 25 2018

Mathematica

Table[FromDigits[RealDigits[n, 6], 3], {n, 0, 100}]

Formula

a(n) = 3*a(n/6) if n == 0 (mod 6); otherwise a(n) = a(n-1)+1.