A121253 a(n) = a(n-1)*a(n-3)+1 with a(0)=a(1)=a(2)=0.

0, 0, 0, 1, 1, 1, 2, 3, 4, 9, 28, 113, 1018, 28505, 3221066, 3279045189, 93469183112446, 301070407771273987437, 987223472152664180906141290594, 92274971491542102812339702600558728264132925

Offset

0,7

Comments

Analog of A007660 a(n)=a(n-1)*a(n-2)+1. What is the equivalent continued fraction and asymptotic representation?

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..26 (shortened by N. J. A. Sloane, Jan 13 2019)

Mathematica

RecurrenceTable[{a[0]==a[1]==a[2]==0, a[n]==a[n-1]a[n-3]+1}, a, {n, 20}] (* Harvey P. Dale, Dec 30 2011 *)

Prog

(Magma) I:=[0, 0, 0]; [n le 3 select I[n] else Self(n-1)*Self(n-3)+1: n in [1..20]]; // Vincenzo Librandi, Nov 14 2011

Crossrefs

Cf. A007660.

Sequence in context: A282571 A063455 A001144 * A014118 A007704 A328836

Adjacent sequences: A121250 A121251 A121252 * A121254 A121255 A121256

Keyword

nonn,easy

Author

Jonathan Vos Post, Aug 22 2006

Extensions

More terms from Vincenzo Librandi, Nov 14 2011

Status

approved