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A056375 Number of step shifted (decimated) sequences using a maximum of six different symbols. 8
6, 36, 126, 756, 2016, 23976, 46956, 435456, 1683576, 15128856, 36284472, 547204896, 1088416056, 13060989936, 58782164616, 352913845536, 1057916846196, 16926689693376, 33853322280036, 457078896068256, 1828085963706576 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A056371 for an explanation of step shifts.

REFERENCES

M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1275

R. C. Titsworth, Equivalence classes of periodic sequences, Illinois J. Math., 8 (1964), 266-270.

FORMULA

The cycle index is implicit in Titsworth.

Sequences A056372-A056375 fit a general formula, implemented in PARI/GP as follows: { a(m,n) = sum(k=1, n, if(gcd(k, n)==1, m^sumdiv(n, d, eulerphi(d)/znorder(Mod(k, d))), 0); ) / eulerphi(n) }. - Max Alekseyev, Nov 08 2007

MATHEMATICA

a[m_, n_] := (1/EulerPhi[n])*Sum[If[GCD[k, n] == 1, m^DivisorSum[n, EulerPhi[#]/MultiplicativeOrder[k, #] &], 0], {k, 1, n}]; Table[a[6, n], {n, 1, 21}] (* Jean-Fran├žois Alcover, Dec 04 2015 *)

CROSSREFS

Cf. A056414.

A row or column of A132191.

Sequence in context: A264366 A061707 A253945 * A018214 A181478 A223841

Adjacent sequences:  A056372 A056373 A056374 * A056376 A056377 A056378

KEYWORD

nonn

AUTHOR

Marks R. Nester

EXTENSIONS

More terms from Max Alekseyev, Nov 08 2007

STATUS

approved

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Last modified October 21 09:06 EDT 2018. Contains 316406 sequences. (Running on oeis4.)