OFFSET
0,4
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,7,0,-3).
FORMULA
G.f.: x*(1 + x - 3*x^2)/(1 - 7*x^2 + 3*x^4).
a(n) = 7*a(n-2) - 3*a(n-4).
a(n) = (2 - (-1)^n)*a(n-1) + (2 + (-1)^n)*a(n-2) for n > 1, a(0)=0, a(1)=1.
a(2k) = A190972(k).
MATHEMATICA
LinearRecurrence[{0, 7, 0, -3}, {0, 1, 1, 4}, 34]
RecurrenceTable[{a[0] == 0, a[1] == 1, a[n] == (2 - (-1)^n) a[n - 1] + (2 + (-1)^n) a[n - 2]}, a, {n, 33}]
PROG
(PARI) concat(0, Vec(x*(1+x-3*x^2)/(1-7*x^2+3*x^4) + O(x^99))) \\ Altug Alkan, Aug 27 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ilya Gutkovskiy, Aug 27 2016
STATUS
approved