

A272038


Somos's sequence {b(9,n)} defined in comment in A078495: a(0)=a(1)=...=a(20)=1; for n>=21, a(n)=(a(n1)*a(n20)+a(n10)*a(n11))/a(n21).


1



1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 19, 31, 51, 81, 123, 179, 251, 341, 451, 1045, 1691, 2451, 3459, 4977, 7467, 11679, 18755, 30349, 48763, 100474, 282777, 679512, 1391391, 2547414, 4327101
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,22


LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..578


PROG

(Ruby)
def b(k, n)
b = Array.new(2 * k + 3, 1)
(2 * k + 3..n).each{i
j = (b[i  1] * b[i  2 * k  2] + b[i  k  1] * b[i  k  2]) / b[i  2 * k  3].to_r
j = j.to_i if j.denominator == 1
b[i] = j
}
b[0..n]
end
p b(9, n) # Seiichi Manyama, May 04 2016


CROSSREFS

Cf. A006721, A078495, A268199, A271954, A271948, A271949, A271950, A271952, A271955.
Sequence in context: A332166 A017904 A143290 * A044961 A044823 A048309
Adjacent sequences: A272035 A272036 A272037 * A272039 A272040 A272041


KEYWORD

nonn


AUTHOR

Vladimir Shevelev and Peter J. C. Moses, Apr 18 2016


STATUS

approved



