OFFSET
0,4
COMMENTS
A two-way infinite sequences which is palindromic (up to sign). - Michael Somos, Mar 21 2003
LINKS
Index entries for linear recurrences with constant coefficients, signature (1, 0, 2, -2, 1, -2, 1, -2, 2, 0, 1, -1).
FORMULA
G.f.: 1 / ((1 - x) * (1 - x^3)^2 * (1 - x^5)).
a(-12 - n) = -a(n). a(n) = a(n-1) + 2*a(n-3) - 2*a(n-4) + a(n-5) - 2*a(n-6) + a(n-7) - 2*a(n-8) + 2*a(n-9) + a(n-11) - a(n-12). - Michael Somos, Mar 21 2003
PROG
(PARI) {a(n) = if( n<-11, -a(-12 - n), if( n<0, 0, polcoeff( 1 / ((1 - x) * (1 - x^3)^2 * (1 - x^5)) + x * O(x^n), n)))} /* Michael Somos, Mar 21 2003 */
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved