OFFSET
0,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..14 (shortened by N. J. A. Sloane, Jan 13 2019)
FORMULA
a(n) ~ c^(A058265^n), where c = 1.3319334322065642848267... - Vaclav Kotesovec, Jun 15 2019
MATHEMATICA
RecurrenceTable[{a[0]==a[1]==a[2]==2, a[n] == a[n-1]*a[n-2]*a[n-3] - 1}, a, {n, 0, 15}] (* G. C. Greubel, Jun 07 2019 *)
nxt[{a_, b_, c_}]:={b, c, a*b*c-1}; NestList[nxt, {2, 2, 2}, 10][[All, 1]] (* Harvey P. Dale, Jun 25 2020 *)
PROG
(Magma) I:=[2, 2, 2]; [n le 3 select I[n] else Self(n-1)*Self(n-2)* Self(n-3)-1: n in [1..12]]; // Vincenzo Librandi, Nov 14 2011
(PARI) a(n) = if(n<3, 2, a(n-1)*a(n-2)*a(n-3) - 1);
vector(12, n, n--; a(n)) \\ G. C. Greubel, Jun 07 2019
(Sage)
def a(n):
if (n==0 or n==1 or n==2): return 2
else: return a(n-1)*a(n-2)*a(n-3) - 1
[a(n) for n in (0..12)] # G. C. Greubel, Jun 07 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post, Aug 22 2006
EXTENSIONS
Data corrected by Vincenzo Librandi, Nov 14 2011
STATUS
approved