OFFSET
1,1
COMMENTS
For primes less than 10^6, the density of these primes is near 0.6075.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1600
Nadav Kohen, Uniform Recurrence in the Motzkin Numbers and Related Sequences mod p, arXiv:2403.00149 [math.CO], 2024.
Nadav Kohen, The Automatic Study of Constant Term Sequences Modulo Prime Powers, Ph. D. Thesis, Indiana Univ. ProQuest (2025) 32282826. See pp. 45, 119.
Narad Rampersad and Jeffrey Shallit, Congruence properties of combinatorial sequences via Walnut and the Rowland-Yassawi-Zeilberger automaton, arXiv:2110.06244 [math.CO], 2021.
MATHEMATICA
nn=1000; a=b=1; t=Join[{1}, Table[c=((2n-1)b+3(n-1)a)/n; a=b; b=c; c, {n, 2, nn}]]; pLst={}; Do[p=Prime[n]; k=1; While[k<p && Mod[t[[k]], p]>0, k++ ]; If[k==p, AppendTo[pLst, p]], {n, PrimePi[nn]}]; pLst
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Oct 24 2005
STATUS
approved
