OFFSET
1,1
LINKS
J. A. Sellers, Infinitely Many Composite NSW Numbers: An Inductive Proof
J. A. Sellers and H. Williams, On the Infinitude of Composite NSW Numbers
MATHEMATICA
a[0] = 1; a[1] = 7; a[n_] := a[n] = 6a[n - 1] - a[n - 2]; a /@ Select[ Range[23], !PrimeQ[ a[ # ]] &] (* Robert G. Wilson v, Jun 09 2004 *)
nxt[{a_, b_}]:={b, 6b-a}; Select[NestList[nxt, {1, 7}, 30][[;; , 1]], CompositeQ] (* Harvey P. Dale, Mar 11 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jun 07 2004
EXTENSIONS
More terms from Robert G. Wilson v, Jun 09 2004
STATUS
approved