A047489 - OEIS

A047489

Numbers that are congruent to {1, 2, 3, 5, 7} mod 8.

1, 2, 3, 5, 7, 9, 10, 11, 13, 15, 17, 18, 19, 21, 23, 25, 26, 27, 29, 31, 33, 34, 35, 37, 39, 41, 42, 43, 45, 47, 49, 50, 51, 53, 55, 57, 58, 59, 61, 63, 65, 66, 67, 69, 71, 73, 74, 75, 77, 79, 81, 82, 83, 85, 87, 89

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OFFSET

1,2

COMMENTS

Numbers n such that A002817(n) is divisible by n. [Bruno Berselli, Dec 11 2013]

LINKS

Bruno Berselli, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).

FORMULA

G.f.: x*(x+1)*(x^4+x^3+x^2+1)/((x-1)^2*(x^4+x^3+x^2+x+1)). [Colin Barker, Jun 22 2012]

MATHEMATICA

LinearRecurrence[{1, 0, 0, 0, 1, -1}, {1, 2, 3, 5, 7, 9}, 80] (* Harvey P. Dale, Jan 06 2026 *)

CROSSREFS

Cf. A002817.

Sequence in context: A325600 A195921 A175089 * A375488 A196499 A392867

Adjacent sequences: A047486 A047487 A047488 * A047490 A047491 A047492

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved