OFFSET
0,4
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,2,0,0,-1).
FORMULA
G.f.: 1 + x*U(0) where U(k)= 1 + x/(1 - x*(2*k+2)/(1+x*(2*k+2) - 1/((2*k+2) + 1 - (2*k+2)*x/(x + 1/U(k+1))))) ; (continued fraction, 5-step). - Sergei N. Gladkovskii, Oct 07 2012
MATHEMATICA
LinearRecurrence[{0, 0, 2, 0, 0, -1}, {1, 1, 1, 3, 1, 1}, 92] (* Georg Fischer, Feb 25 2022 *)
PROG
(PARI) /* first version */ contfrac((besseli(0, 1/2)/besseli(1, 1/2)-1)/2)[n+1] /* alternate version */ 2/3*n*!(n%3)+1
CROSSREFS
KEYWORD
cofr,easy,nonn
AUTHOR
Thomas Baruchel, Jan 18 2005
STATUS
approved