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A047486 Numbers that are congruent to {0, 1, 3, 5, 7} mod 8. 4
0, 1, 3, 5, 7, 8, 9, 11, 13, 15, 16, 17, 19, 21, 23, 24, 25, 27, 29, 31, 32, 33, 35, 37, 39, 40, 41, 43, 45, 47, 48, 49, 51, 53, 55, 56, 57, 59, 61, 63, 64, 65, 67, 69, 71, 72, 73, 75, 77, 79, 80, 81, 83, 85, 87, 88, 89 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Also nonnegative integers primitively represented by x^2 - y^2. - Ray Chandler, Aug 23 2014

LINKS

Ray Chandler, Table of n, a(n) for n = 1..10000

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

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

FORMULA

G.f.: x^2*(x^2 + 1)*(1 + x)^2/((x^4 + x^3 + x^2 + x + 1)*(x - 1)^2). - R. J. Mathar, Oct 07 2011

From Wesley Ivan Hurt, Dec 28 2016: (Start)

a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6.

a(n) = (40*n - 40 - 2*(n mod 5) - 2*((n+1) mod 5) - 2*((n+2) mod 5) + 3*((n+3) mod 5) + 3*((n+4) mod 5))/25. (End)

CROSSREFS

Cf. A065091, A094572.

Sequence in context: A062958 A184996 A153309 * A229838 A191257 A120212

Adjacent sequences:  A047483 A047484 A047485 * A047487 A047488 A047489

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified July 21 18:40 EDT 2017. Contains 289643 sequences.