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A007227 Number of distinct perforation patterns for deriving (v,b)=(n+2,n) punctured convolutional codes from (3,1).
(Formerly M4624)
0
9, 42, 236, 1287, 7314, 41990, 245256, 1448655, 8649823, 52106040, 316360752, 1933910820, 11893566078, 73537906926, 456864894288, 2850557192175, 17854854154215, 112230508880490, 707714010205020, 4475876883386895 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

REFERENCES

G. Begin, On the enumeration of perforation patterns for punctured convolutional codes, Séries Formelles et Combinatoire Algébrique, 4th colloquium, 15-19 Juin 1992, Montréal, Université du Québec à Montréal, pp. 1-10.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=2..21.

MAPLE

with(numtheory):P:=proc(b, v0) local k: RETURN(add(phi(k)*(1+z^k)^(v0*(b/k)), k=divisors(b))/b): end; seq(coeff(P(b, 3), z, b+2), b=2..40); (Pab Ter)

CROSSREFS

Sequence in context: A289364 A074443 A221425 * A224836 A195975 A185918

Adjacent sequences:  A007224 A007225 A007226 * A007228 A007229 A007230

KEYWORD

nonn

AUTHOR

Simon Plouffe

EXTENSIONS

More terms from Pab Ter (pabrlos2(AT)yahoo.com), Nov 13 2005

STATUS

approved

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Last modified April 25 21:06 EDT 2019. Contains 322461 sequences. (Running on oeis4.)