OFFSET
0,2
LINKS
FORMULA
a(n) = a(n-2) + A022088(n-1).
a(n) = 2*a(n-2) + a(n-3).
a(n) = - a(n-3) + 10*A000045(n-1) for n >= 3.
G.f.: (1+2*x)^2/((1+x)*(1-x-x^2)). - Joerg Arndt, Apr 13 2024
EXAMPLE
a(3) = 2*4 + 1 = 9. Also a(3) = -1 + 10*1 = 9.
MATHEMATICA
LinearRecurrence[{0, 2, 1}, {1, 4, 6}, 50] (* Amiram Eldar, Apr 11 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Apr 08 2024
STATUS
approved