OFFSET
1,1
COMMENTS
LINKS
FORMULA
a(n) = (5-3*(-1)^n)*5^(1/4*(2*n-1+(-1)^n))/2.
G.f.: x*(4+5*x)/(1-5*x^2).
MATHEMATICA
LinearRecurrence[{0, 5}, {4, 5}, 30] (* Harvey P. Dale, Dec 20 2021 *)
PROG
(Magma) [ n le 2 select n+3 else 5*Self(n-2): n in [1..29] ];
(PARI) Vec(x*(4+5*x)/(1-5*x^2) + O(x^30)) \\ Jinyuan Wang, Mar 23 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Jul 21 2009
STATUS
approved