A007879 Chimes made by clock striking the hour and half-hour.

1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 1, 12, 1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 1, 12, 1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 1, 12

Offset: 0

Author

Jan Wolitzky

Keywords

• nonn
• easy

Comments

Periodic sequence with period 24. - Michel Marcus, Jul 17 2013

Links

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

Crossrefs

Cf. A010881, A057979.

Programs

Mathematica

CoefficientList[Series[(1+x-x^2-x^24-13x^25+x^26+12x^27)/((1-x^24)(1-x^2)^2),{x,0,71}],x] (* Stefano Spezia, Mar 27 2022 *)

PARI

a(n)= 1 + ((n-1)*(1-(-1)^n)/4) % 12 \\ Michel Marcus, Jul 17 2013

Formula

From Hieronymus Fischer, Sep 25 2007: (Start)

G.f.: 1/(1-x^2)+x(12x^26-13x^24+1)/((1-x^24)(1-x^2)^2).

G.f.: (1+x-x^2-x^24-13x^25+x^26+12x^27)/((1-x^24)(1-x^2)^2).

a(n) = 1 + ((n-1)*(1-(-1)^n)/4) mod 12.

a(n) = 1 + ((n-1)*(n mod 2)/2) mod 12. (End)