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A135690 Recursion based on J. Mortensen's programming page for Per Nørgård's "infinite series" music composition sequence technique. 0
0, 1, -1, 2, -4, -2, -6, 0, -12, -8, -16, -4, -28, -20, -36, -12, -60, -44, -76, -28, -124, -92, -156, -60, -252, -188, -316, -124, -508, -380, -636, -252, -1020, -764, -1276, -508, -2044, -1532, -2556, -1020, -4092, -3068, -5116, -2044, -8188, -6140, -10236, -4092, -16380, -12284, -20476 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Per Nørgård is a well-known classical music composer and his sequence method dates back to 1959. This sequence is new and was my third attempt to translate the web page into Mathematica programming.

The composer Per Nørgård's name is also written in the OEIS as Per Noergaard.

REFERENCES

http : // www.pernoergaard.dk/eng/strukturer/uendelig/ukonstruktion05.html

LINKS

Table of n, a(n) for n=1..51.

FORMULA

pn(n) = If[Mod[n, 2] == 0, pn(n - 2) - (pn(n - 1) - pn(n - 2)), pn(n - 1) - (pn(n - 3) - pn(n - 4))].

Empirical G.f.: -x^2*(2*x-1)*(3*x^2+1) / ((x-1)*(2*x^4-1)). - Colin Barker, Jan 26 2013

MATHEMATICA

pn[0] = 0; pn[1] = 1; pn[2] = -1; pn[3] = 2; pn[n_] := pn[n] = If[Mod[n, 2] == 0, pn[n - 2] - (pn[n - 1] - pn[ n - 2]), pn[n - 1] - (pn[n - 3] - pn[n - 4])] a = Table[pn[n], {n, 0, 50}]

CROSSREFS

Sequence in context: A198723 A198914 A207868 * A010241 A278526 A162630

Adjacent sequences:  A135687 A135688 A135689 * A135691 A135692 A135693

KEYWORD

uned,sign

AUTHOR

Roger L. Bagula, Feb 19 2008

STATUS

approved

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Last modified July 23 11:44 EDT 2019. Contains 325254 sequences. (Running on oeis4.)