A343109 Numbers having no divisor of the form 8*k + 5.

1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 14, 16, 17, 18, 19, 22, 23, 24, 27, 28, 31, 32, 33, 34, 36, 38, 41, 43, 44, 46, 47, 48, 49, 51, 54, 56, 57, 59, 62, 64, 66, 67, 68, 71, 72, 73, 76, 79, 81, 82, 83, 86, 88, 89, 92, 94, 96, 97, 98, 99, 102, 103, 107, 108, 112, 113

Offset

1,2

Comments

Numbers not divisible by at least one of 5, 13, 21, ...

Links

Jianing Song, Table of n, a(n) for n = 1..10000

Example

9 is a term since it has no divisor congruent to 5 modulo 8.

Prog

(PARI) res(n, a, b) = sumdiv(n, d, (d%a) == b)
isA343109(n) = (res(n, 8, 5) == 0)

Crossrefs

Numbers having m divisors of the form 8*k + i: A343107 (m=1, i=1), A343108 (m=0, i=3), this sequence (m=0, i=5), A343110 (m=0, i=7), A343111 (m=2, i=1), A343112 (m=1, i=3), A343113 (m=1, i=5), A141164 (m=1, i=7).

Indices of 0 in A188171.

Sequence in context: A004439 A050126 A013939 * A209921 A268377 A201010

Adjacent sequences: A343106 A343107 A343108 * A343110 A343111 A343112

Keyword

nonn,easy

Author

Jianing Song, Apr 05 2021

Status

approved