A024662 n written in fractional base 10/7.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 7410, 7411, 7412, 7413, 7414, 7415, 7416, 7417, 7418, 7419, 7480, 7481, 7482, 7483, 7484, 7485, 7486, 7487, 7488, 7489, 74150, 74151, 74152

Offset: 0

Author

David W. Wilson

Keywords

• nonn
• base
• easy

Comments

To represent a number in base b, if a digit exceeds b-1, subtract b and carry 1. In fractional base a/b, subtract a and carry b.

Links

• Amiram Eldar, Table of n, a(n) for n = 0..10000
• Index entries for sequences related to fractional bases.

Crossrefs

Cf. A245351.

Programs

Mathematica

a[n_] := a[n] = If[n == 0, 0, 10 * a[7 * Floor[n/10]] + Mod[n, 10]]; Array[a, 50, 0] (* Amiram Eldar, Aug 04 2025 *)

PARI

a(n) = if(n == 0, 0, 10 * a(n\10 * 7) + n % 10); \\ Amiram Eldar, Aug 04 2025