



1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1, 2, 7, 2, 4, 5, 4, 8, 1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1, 2, 7, 2, 4, 5, 4, 8, 1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1, 2, 7, 2, 4, 5, 4, 8, 1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1, 2, 7, 2, 4, 5, 4, 8, 1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1, 2, 7, 2, 4, 5, 4, 8, 1, 8, 7, 2, 7, 5, 4, 5, 1, 8, 1
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OFFSET

0,2


LINKS

Muniru A Asiru, Table of n, a(n) for n = 0..1000
R. Bacher and P. Flajolet, Pseudofactorials, Elliptic Functions and Continued Fractions, arXiv:0901.1379 [math.CA], 2009.


FORMULA

From Chai Wah Wu, Nov 30 2018: (Start)
a(n) = a(n2) + a(n3)  a(n5)  a(n6) + a(n8) for n > 7 (conjectured).
G.f.: (8*x^7  4*x^6 + 3*x^5 + 8*x^4 + 7*x^3  6*x^2  8*x  1)/((x  1)*(x + 1)*(x^6  x^3 + 1)) (conjectured). (End)


MAPLE

a:= proc(n) option remember; `if`(n=0, 1, (1)^n*add(binomial(n1, k)*a(k)*a(n1k), k=0..n1)) end: seq(modp(a(n), 9), n=0..100); # Muniru A Asiru, Jul 29 2018


MATHEMATICA

b[0] = 1;
b[n_] := b[n] = (1)^n Sum[Binomial[n1, k] b[k] b[nk1], {k, 0, n1}];
a[n_] := Mod[b[n], 9]; Table[a[n], {n, 0, 100}] (* JeanFrançois Alcover, Jul 29 2018 *)


CROSSREFS

Sequence in context: A179044 A084254 A255696 * A198928 A155068 A244839
Adjacent sequences: A144747 A144748 A144749 * A144751 A144752 A144753


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Feb 08 2009


STATUS

approved



