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A122159
Period of A002067 modulo prime(n).
2
1, 1, 8, 3, 10, 24, 32, 18, 22, 56, 30, 72, 80, 42, 23, 104, 29, 120, 66, 70, 144, 39, 41, 176, 192, 200, 51, 53, 216, 224, 63, 130, 272, 69, 296, 150, 312, 162, 166, 344, 178, 360, 95, 384, 392, 99, 105, 222, 226, 456, 464, 238, 480, 125, 512, 131, 536, 270, 552
OFFSET
1,3
FORMULA
a(n) = A122149(A000040(n)).
EXAMPLE
A002067 modulo 5 is 1, 1, 2, 2, 4, 4, 3, 3, 1, 1, 2, 2, 4, 4, 3, 3, 1, 1, ... with period 8.
MATHEMATICA
max = 100; se = Series[InverseErf[2*x/Sqrt[Pi]], {x, 0, 2*max + 1}]; a[n_] := (2 n + 1)!/2^n*Coefficient[se, x, 2*n + 1]; A002067 = Table[a[n], {n, 0, max}]; period[lst_List] := Catch[lg = If[Length[lst] <= 5, 2, 5]; lst1 = lst[[1 ;; lg]]; km = Length[lst] - lg; Do[If[lst1 == lst[[k ;; k + lg - 1]], Throw[k - 1]]; If[k == km, Throw[0]], {k, 2, km}]]; Table[ period[Mod[A002067, Prime[n]] // Reverse] , {n, 1, 15}] (* Jean-François Alcover, Dec 17 2012 *)
CROSSREFS
Sequence in context: A246671 A069610 A257811 * A365445 A069200 A069218
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 06 2008
EXTENSIONS
a(9)-a(15) from Jean-François Alcover, Dec 17 2012
More terms from Jinyuan Wang, Jul 30 2022
STATUS
approved