A331841 When expressed in base 2 and then interpreted in base 5, is a multiple of the original number.

0, 1, 3, 6, 9, 10, 18, 21, 27, 30, 54, 57, 60, 63, 89, 90, 108, 114, 126, 130, 178, 180, 189, 228, 300, 356, 378, 390, 630, 712, 780, 900, 1170, 1299, 1300, 1890, 1953, 2340, 2370, 2730, 3510, 3900, 3906, 4740, 7020, 7110, 7410, 7800, 8100, 8190, 9261, 11700

Offset

1,3

Links

Dimiter Skordev, Table of n, a(n) for n = 1..138 (terms less than 10^7).

Dimiter Skordev, Python script

Example

30 = 11110_2; 11110_5 = 780 = 26*30.

Mathematica

Prepend[Select[Range[12000], Divisible[FromDigits[IntegerDigits[#, 2], 5], #] &], 0] (* Amiram Eldar, Jan 29 2020 *)

Prog

(PARI) isok(n) = (n == 0) || (fromdigits(digits(n, 2), 5) % n) == 0; \\ Michel Marcus, Jan 29 2020
(Magma) [0] cat [k:k in [1..12000]|Seqint(Intseq(Seqint(Intseq(k, 2))), 5) mod k eq 0]; // Marius A. Burtea, Jan 29 2020

Crossrefs

Cf. (with base 2 and b): A062845 (b=3), A062846 (b=4), A062847 (b=6), A062848 (b=7), A062849 (b=8), A062850 (b=9), A032533 (b=10).

Sequence in context: A166047 A310141 A348550 * A223999 A107084 A224353

Adjacent sequences: A331838 A331839 A331840 * A331842 A331843 A331844

Keyword

base,nonn

Author

Dimiter Skordev, Jan 29 2020

Status

approved