login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A031362 Number of coincidence site modules of index 10n+1 with 10-fold symmetry in plane. 0
1, 4, 0, 4, 4, 0, 4, 4, 0, 0, 4, 0, 8, 4, 0, 4, 0, 0, 4, 4, 0, 4, 0, 0, 4, 4, 0, 4, 4, 0, 0, 4, 0, 4, 16, 0, 0, 0, 0, 0, 4, 0, 4, 4, 0, 16, 4, 0, 0, 4, 0, 0, 4, 0, 4, 0, 0, 4, 0, 0, 4, 0, 0, 4, 4, 0, 4, 16, 0, 4, 4, 0, 0, 0, 0, 4, 4, 0, 16, 0, 0, 4, 4, 0, 0, 0, 0, 0, 4, 0, 0, 4, 0, 0, 4, 0, 8, 4, 0, 4 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The Dirichlet g.f. is sum_{n>=0} a(n+1)/(1+10n)^s. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2010]

REFERENCES

M. Baake, "Solution of coincidence problem...", in R. V. Moody, ed., Math. of Long-Range Aperiodic Order, Kluwer 1997, pp. 9-44.

FORMULA

Dirichlet series: Product ((1+p^(-s))/(1-p^(-s)))^2 (p=1 mod 5).

MAPLE

Contribution from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2010: (Start)

read("transforms") : maxOrd := 1000 :

ZetaNum := proc(p, nmax, f) local n ; L := [1, seq(0, n=2..p-1), f, seq(0, n=p+1..nmax)] ; end proc:

Zeta := proc(p, nmax, f) local L, e; L := [1, seq(0, n=2..nmax)] ; for e from 1 do if p^e > nmax then break; else L := subsop(p^e=f^e, L) ; end if; end do: L ; end proc:

Zetap := [1, seq(0, n=2..maxOrd)] : for e from 1 to maxOrd by 5 do if isprime(e) then ZetaNum(e, maxOrd, 1) ; Zetap := DIRICHLET(Zetap, %) ; Zeta(e, maxOrd, 1) ; Zetap := DIRICHLET(Zetap, %) ; end if; end do:

Zetap := DIRICHLET(Zetap, Zetap) ; seq( Zetap[1+10*e], e=0..(nops(Zetap)-1)/10) ; (End)

CROSSREFS

Sequence in context: A016680 A062524 A152856 * A198414 A110854 A021716

Adjacent sequences:  A031359 A031360 A031361 * A031363 A031364 A031365

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 15:28 EST 2012. Contains 205630 sequences.