A375922 a(n) = (a(n-3)*a(n-9) + a(n-1)*a(n-11))/a(n-12) with a(0) = ... = a(11) = 1.
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 6, 9, 13, 19, 28, 41, 79, 163, 490, 972, 1785, 4270, 9483, 19251, 41603, 100739, 259579, 997371, 3297339, 12754875, 33992883, 94594611, 363844867, 1139238123, 3317604094, 12075672425, 56552033036, 254310500890
Offset: 0
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..345
- Mohamed Bensaid, Sato tau functions and construction of Somos sequence, arXiv:2409.05911 [math.NT], 2024.
- Eric Weisstein's World of Mathematics, Somos Sequence.
Crossrefs
Cf. A375621.
Programs
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Maple
a:= proc(n) option remember; `if`(n<12, 1, (a(n-3)*a(n-9)+a(n-1)*a(n-11))/a(n-12)) end: seq(a(n), n=0..42); # Alois P. Heinz, Sep 02 2024 -
Mathematica
a[n_] := a[n] = If[n < 12, 1, (a[n-3]*a[n-9] + a[n-1]*a[n-11]) / a[n-12]]; Array[a, 40, 0] (* Amiram Eldar, Sep 02 2024 *)
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PARI
seq(n)={my(a=vector(n+1,i,1)); for(n=13, #a, a[n] =(a[n-3]*a[n-9]+a[n-1]*a[n-11])/a[n-12]); a} \\ Andrew Howroyd, Sep 03 2024
Comments