A062891 When expressed in base 3 and then interpreted in base 9, is a multiple of the original number.

0, 1, 2, 3, 6, 9, 13, 18, 26, 27, 34, 39, 47, 54, 78, 81, 91, 102, 117, 121, 141, 162, 182, 234, 242, 243, 262, 273, 306, 351, 363, 423, 486, 546, 702, 726, 729, 757, 786, 819, 918, 1048, 1053, 1089, 1093, 1183, 1269, 1458, 1514, 1638, 2106, 2178, 2186, 2187

Offset: 1

Author

Erich Friedman, Jul 21 2001

Keywords

• base
• nonn

Examples

			13 in base 3 is 111, which interpreted in base 9 is 91 = 7*13.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..751 [offset shifted by _Georg Fischer_, Jun 15 2021]

Crossrefs

Cf. A007089 (base 3), A007095 (base 9), A037314 (base 3 -> 9).

Other digit spreads: A062846 (binary), A343550 (decimal).

Programs

Maple

q:= n-> (l-> n=0 or 0=irem(add(l[i]*9^(i-1),
         i=1..nops(l)), n))(convert(n, base, 3)):
select(q, [$0..3000])[];  # Alois P. Heinz, Apr 20 2021

Mathematica

Join[{0},Select[Range[2200],Divisible[FromDigits[IntegerDigits[#,3],9],#]&]] (* Harvey P. Dale, Apr 11 2017 *)

Extensions

Offset changed to 1 by Kevin Ryde, Apr 24 2021