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A038342 G.f.: -1/(- 1 + 3 x + 3 x^2 - 4 x^3 - x^4 + x^5) 2
1, 3, 12, 41, 146, 511, 1798, 6314, 22187, 77946, 273856, 962142, 3380337, 11876254, 41725295, 146595013, 515037713, 1809501081, 6357387289, 22335644540, 78472648463, 275700866485, 968630080476, 3403123989780 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Middle line of 5-wave sequence A038201.

Let M denotes the 5 X 5 matrix = row by row (1,1,1,1,1)(1,1,1,1,0)(1,1,1,0,0)(1,1,0,0,0)(1,0,0,0,0) and A(n) the vector (x(n),y(n),z(n),t(n),u(n))=M^n*A where A is the vector (1,1,1,1,1) then a(n)=z(n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 02 2002

REFERENCES

Jay Kappraff, Beyond Measure, A Guided Tour Through Nature, Myth and Number, World Scientific, 2002.

P. Steinbach, Golden fields: a case for the heptagon, Math. Mag. 70 (1997), no. 1, 22-31.

LINKS

Index entries for sequences related to linear recurrences with constant coefficients

F. v. Lamoen, Wave sequences

FORMULA

a(n)=3a(n-1)+3a(n-2)-4a(n-3)-a(n-4)+a(n-5). Also a(n)=b(4n+2) with b(n) as in 5-wave sequence A038201.

MATHEMATICA

b = {-1, 3, 3, -4, -1, 1}; p[x_] := Sum[x^(n - 1)*b[[7 - n]], {n, 1, 6}] q[x_] := ExpandAll[x^5*p[1/x]] Table[ SeriesCoefficient[ Series[x/q[x], {x, 0, 30}], n], {n, 0, 30}] - Roger Bagula and Gary Adamson (rlbagulatftn(AT)yahoo.com), Sep 19 2006

CROSSREFS

Cf. A006358: same recurrence formula.

Cf. A066170.

Sequence in context: A038345 A127120 A017940 * A135264 A084529 A017941

Adjacent sequences:  A038339 A038340 A038341 * A038343 A038344 A038345

KEYWORD

nonn

AUTHOR

Floor van Lamoen (fvlamoen(AT)hotmail.com)

EXTENSIONS

More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 02 2002

Edited by N. J. A. Sloane (njas(AT)research.att.com) at the suggestion of Andrew Plewe, Jun 08 2007

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Last modified February 17 19:13 EST 2012. Contains 206085 sequences.