A053842 (Sum of digits of n written in base 7) modulo 7.

0, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 0, 2, 3, 4, 5, 6, 0, 1, 3, 4, 5, 6, 0, 1, 2, 4, 5, 6, 0, 1, 2, 3, 5, 6, 0, 1, 2, 3, 4, 6, 0, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 0, 2, 3, 4, 5, 6, 0, 1, 3, 4, 5, 6, 0, 1, 2, 4, 5, 6, 0, 1, 2, 3, 5, 6, 0, 1, 2, 3, 4, 6, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 0, 1

Offset: 0

Author

Henry Bottomley, Mar 28 2000

Keywords

• base
• nonn

Comments

a(n) is the sixth row of the array in A141803. - Andrey Zabolotskiy, May 18 2016

Links

• G. C. Greubel, Table of n, a(n) for n = 0..5000
• Robert Walker, Self Similar Sloth Canon Number Sequences

Crossrefs

Cf. A010876, A053828, A141803.

Cf. A010060, A053837-A053844.

Programs

Mathematica

Table[Mod[Plus @@ IntegerDigits[n, 7], 7], {n, 0, 50}] (* G. C. Greubel, Nov 02 2017 *)

PARI

a(n) = vecsum(digits(n, 7)) % 7; \\ Michel Marcus, May 18 2016

Formula

a(n) = A010876(A053828(n)). - Andrey Zabolotskiy, May 18 2016