OFFSET
1,3
LINKS
T. D. Noe, Table of n, a(n) for n=1..1000
MATHEMATICA
A008784 = Select[ Range[300], And @@ (Mod[#, 4] == 1 & ) /@ (fi = FactorInteger[#]; If[ fi[[1]] == {2, 1}, Rest[ fi[[All, 1]]], fi[[All, 1]]])& ]; a[n_] := Min[r /. {ToRules[ Reduce[ Mod[r^2 + 1, A008784[[n]]] == 0, r, Integers] /. C[1] -> 0]}]; a[1] = 0; Table[a[n], {n, 1, 63}] (* Jean-François Alcover, Sep 19 2012 *)
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
N. J. A. Sloane, Nov 01 2000
EXTENSIONS
Corrected by T. D. Noe, Apr 19 2007 [The errors were caused by the faulty Maple command "mroot"]
STATUS
approved