OFFSET
1,1
COMMENTS
Fifth column of triangular array T defined in A131074.
Simple continued fraction of (1728521 + sqrt(3040737300437))/230114 = 15.0894426240... - R. J. Mathar, Mar 08 2012
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..8192
Index entries for linear recurrences with constant coefficients, signature (1,0,0,-1,1).
FORMULA
a(n) = a(n-8).
G.f.: x*(15 - 4*x - 6*x^2 - 4*x^3 + 15*x^4)/((1-x)*(1+x^4)).
MATHEMATICA
PadRight[{}, 100, {15, 11, 5, 1, 1, 5, 11, 15}] (* or *) LinearRecurrence[ {1, 0, 0, -1, 1}, {15, 11, 5, 1, 1}, 100] (* Harvey P. Dale, Feb 01 2015 *)
PROG
(PARI) {m=84; for(n=1, m, r=(n-1)%8; print1(if(r==0||r==7, 15, if(r==1||r==6, 11, if(r==2||r==5, 5, 1))), ", "))}
(Magma) m:=84; [ [15, 11, 5, 1, 1, 5, 11, 15][(n-1) mod 8 + 1]: n in [1..m] ];
(Scheme) (define (A131082 n) (list-ref '(15 11 5 1 1 5 11 15) (modulo (- n 1) 8))) ;; Antti Karttunen, Aug 10 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, following a suggestion of Paul Curtz, Jun 14 2007
STATUS
approved