A258712 - OEIS

A258712

Motzkin numbers A001006 read mod 5.

1, 1, 2, 4, 4, 1, 1, 2, 3, 0, 3, 3, 1, 0, 4, 2, 2, 4, 2, 4, 4, 4, 3, 0, 2, 1, 1, 2, 4, 4, 1, 1, 2, 3, 0, 3, 3, 1, 0, 4, 2, 2, 4, 2, 4, 4, 4, 3, 4, 3, 3, 3, 1, 2, 2, 3, 3, 1, 4, 0, 4, 4, 3, 0, 2, 1, 1, 2, 1, 2, 2, 2, 4, 3, 3, 2, 2, 4, 3, 3, 2, 2, 4, 1, 0, 1, 1, 2, 0

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..88.

Anders Hyllengren, Letter to N. J. A. Sloane, Oct 04 1985

MATHEMATICA

b = DifferenceRoot[Function[{b, n}, {3 (n + 1) b[n] + (2 n + 5) b[n + 1] == (n + 4) b[n + 2], b[0] == 1, b[1] == 1}]];

a[n_] := Mod[b[n], 5];

Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Feb 26 2019 *)

PROG

(PARI) a001006(n) = polcoeff((1-x-sqrt((1-x)^2-4*x^2+x^3*O(x^n)))/(2*x^2), n);