A010721 - OEIS

A010721

Period 2: repeat (5,10).

5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10

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OFFSET

0,1

LINKS

Table of n, a(n) for n=0..65.

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

FORMULA

a(n) = -5/2*(-1)^n + 15/2. - Paolo P. Lava, Oct 27 2006

From R. J. Mathar, Oct 20 2008: (Start)

a(n) = 5*A000034(n).

G.f.: 5(1+2x)/((1-x)(1+x)). (End)

MATHEMATICA

Table[5 + 5 Mod[n, 2], {n, 0, 50}] (* Jinyuan Wang, Feb 26 2020 *)

PadRight[{}, 80, {5, 10}] (* Harvey P. Dale, Mar 18 2022 *)

PROG

(PARI) a(n)=n%2*5+5 \\ Charles R Greathouse IV, Jul 13 2016

CROSSREFS

Cf. A176325.

Sequence in context: A276652 A137404 A110643 * A046795 A337545 A229793

Adjacent sequences: A010718 A010719 A010720 * A010722 A010723 A010724

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved