OFFSET
1,1
COMMENTS
For primes in this sequence see A146359.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1) = 421 because continued fraction of (1+sqrt(421))/2 = 17, 5, 3, 1, 1, 1, 2, 26, 2, 1, 1, 1, 3, 5, 13, 5, 3, 1, 1, 1, 2, 26, 2, 1, 1, 1, 3, 5, 13, 5, 3, 1, 1, 1, 2, 26... has period (5, 3, 1, 1, 1, 2, 26, 2, 1, 1, 1, 3, 5, 13) length 14.
MAPLE
A := proc(n) option remember ; local c; try c := numtheory[cfrac](1/2+sqrt(n)/2, 'periodic', 'quotients') ; RETURN(nops(c[2]) ); catch: RETURN(-1) end try ; end: isA146337 := proc(n) if A(n) = 14 then RETURN(true); else RETURN(false); fi; end: for k from 1 do if isA146337(k) then printf("%d, ", k) ; fi; od: # R. J. Mathar, Nov 08 2008
MATHEMATICA
cf14Q[n_]:=Module[{s=(1+Sqrt[n])/2}, !IntegerQ[s]&&Length[ ContinuedFraction[ s][[2]]] == 14]; Select[Range[1000], cf14Q] (* Harvey P. Dale, Oct 15 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Oct 30 2008
EXTENSIONS
More terms from R. J. Mathar, Nov 08 2008
STATUS
approved