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A091086 a(n) = A000975(n) mod 10. 0
0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0, 1, 2, 5, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

A000975(0), A000975(1), A000975(2), A000975(3) repeating.

LINKS

Table of n, a(n) for n=0..104.

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

FORMULA

G.f.: x*(1 + 2*x + 5*x^2)/(1 - x^4).

E.g.f.: 2*exp(x) - exp(-x) - cos(x) - 2*sin(x).

a(n) = 2 - (-1)^n - cos(Pi*n/2) - 2*sin(Pi*n/2).

a(n) = (1/12)*(19*(n mod 4) - 5*((n+1) mod 4) + ((n+2) mod 4) + ((n+3) mod 4)). - Paolo P. Lava, Jul 16 2008

a(n+4) = a(n). - G. C. Greubel, Sep 26 2017

2*a(n) = (n mod 2) + (n mod 4)^2. - Bruno Berselli, Oct 18 2018

MATHEMATICA

CoefficientList[Series[x (1 + 2 x + 5 x^2)/(1 - x^4), {x, 0, 50}], x] (* G. C. Greubel, Sep 26 2017 *)

PadRight[{}, 120, {0, 1, 2, 5}] (* Harvey P. Dale, Apr 30 2022 *)

PROG

(PARI) x='x+O('x^50); Vec(x*(1+2*x+5*x^2)/(1-x^4)) \\ G. C. Greubel, Sep 26 2017

CROSSREFS

Sequence in context: A159986 A065452 A004598 * A336686 A118349 A341268

Adjacent sequences: A091083 A091084 A091085 * A091087 A091088 A091089

KEYWORD

nonn,easy

AUTHOR

Paul Barry, Dec 18 2003

STATUS

approved

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Last modified January 27 13:35 EST 2023. Contains 359841 sequences. (Running on oeis4.)