

A135564


Modulo 2 second differential integer sequence based on the Nørgård type form: second differential form as = a(n)  2*a(n1) + a(n2).


1



0, 1, 3, 1, 2, 3, 4, 2, 1, 0, 1, 7, 7, 10, 2, 2, 1, 7, 1, 10, 1, 2, 6, 6, 14, 12, 3, 2, 12, 8, 0, 11, 1, 14, 8, 20, 8, 7, 9, 2, 11, 5, 1, 0, 4, 24, 0, 10, 20, 17, 2, 2, 9, 11, 5, 27, 10, 17, 20, 24, 8, 13, 11, 19, 12, 16, 15, 18, 22, 45, 12, 15, 28, 9, 1, 9, 2, 42, 7, 36, 13, 10, 16, 7, 6, 12, 1, 30, 4
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OFFSET

1,3


COMMENTS

This sequence related to a Bornvon Karman phonon model as well as the Nørgård infinite series; also related to my Ulam experiments.
The composer Per Nørgård's name is also written in the OEIS as Per Noergaard.


LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000
Jørgen Mortensen, Construction by programming


FORMULA

p(i) = If[Mod[i, 2] == 0, p(i  2)  (p(Floor[i/2])  2*([Abs[Floor[i/2]  1]) + p(Abs[Floor[i/2]  2])), p(i  1)  ( p(Abs[Floor[i/2]  2])  2*p(Abs[Floor[i/2]  3]) + p(Abs[Floor[i/2]  4]) )].


MATHEMATICA

p[0] = 0; p[1] = 1; p[2] = 3; p[3] = p[0]  1; p[4] = p[3]  1; p[i_]:= If[Mod[i, 2] == 0, p[i  2]  (p[Floor[i/2]]  2*p[ Abs[Floor[i/2]  1]] + p[Abs[ Floor[i/2]  2]]), p[i  1]  (p[Abs[ Floor[i/2]  2]]  2*p[Abs[Floor[i/2]  3]] + p[Abs[Floor[i/2]  4]])]; b = Table[p[n], {n, 0, 100}]


CROSSREFS

Cf. A122581.
Sequence in context: A211948 A021766 A286357 * A110063 A260313 A050056
Adjacent sequences: A135561 A135562 A135563 * A135565 A135566 A135567


KEYWORD

uned,sign


AUTHOR

Roger L. Bagula, Feb 23 2008


STATUS

approved



