

A137403


A multiswitched integer differentialtype sequence designed to be mostly odd: two types of integer differential sequences are switched in a way that is made odd: 1) a(n)=2*a(n1)a(n2); 2) a(n)=3*a(n1)3*a(n2)+a(n3); the one back versions are 3) a(n)=2*a(n2)a(n3); 4) a(n)=3*a(n2)3*a(n3)+a(n4).


0



2, 3, 5, 4, 3, 3, 3, 4, 3, 5, 2, 7, 12, 17, 17, 22, 27, 27, 27, 22, 27, 17, 32, 7, 18, 43, 43, 68, 93, 93, 93, 68, 93, 43, 118, 7, 132, 257, 257, 382, 507, 507, 507, 382, 507, 257, 632, 7, 618, 1243
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OFFSET

1,1


COMMENTS

The object is to choose the options so that the most likely outcome is odd; 33 out of the first 50 terms are odd.
Apply[Plus, Table[If[Mod[a0[[n]], 2] == 1, 1, 0], {n, 1, Length[a0]}]].


LINKS

Table of n, a(n) for n=1..50.


MATHEMATICA

Clear[a] a[1] = 2; a[2] = 3; a[3] = 5; a[n_] := a[n] = If[Mod[3*a[n  1]  3*a[n  2] + a[n  3], 2] == 0, If[Mod[2*a[n  1]  a[n  2], 3] == 0, 2*a[n  1]  a[n  2], 2*a[n  2]  a[n  3]], If[Mod[3*a[n  1]  3*a[n  2] + a[n  3], 3] == 0, 3*a[n  2]  3*a[n  3] + a[n  4], 3*a[n  1]  3*a[n  2] + a[n  3]]] a0=Table[a[n], {n, 1, 50}]


CROSSREFS

Sequence in context: A284278 A330080 A068508 * A082233 A330806 A058981
Adjacent sequences: A137400 A137401 A137402 * A137404 A137405 A137406


KEYWORD

tabl,sign


AUTHOR

Roger L. Bagula, Apr 14 2008, Apr 15 2008


STATUS

approved



