A055622 - OEIS

A055622

Minimum solution for tri-color tower of Hanoi, restricted so like colors can't be together.

1, 3, 7, 19, 43, 99, 235, 535, 1239, 2879, 6619, 15323, 35451, 81823, 189263, 437543, 1011059, 2337731, 5403987, 12491223, 28877687, 66755519, 154315883, 356738411, 824668747, 1906384015, 4407016991, 10187707927, 23550975203

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..29.

William H. Paulsen, Tri-color Tower of Hanoi

FORMULA

a(n) = a(n-1) + 2 a(n-2) + 7 a(n-3) - 5 a(n-4) - 8 a(n-5) - 14 a(n-6) + 2 a(n-7) + 4 a(n-8) + 4 a(n-9) + 8 a(n-10).

G.f.: x*(1+2*x+2*x^2-x^3-6*x^4-8*x^5-10*x^6-8*x^7-4*x^8)/ ((1-x) * (2*x^5+3*x^3-1) * (4*x^4+6*x^3+2*x^2-1)). [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]

CROSSREFS

Sequence in context: A376197 A192301 A350249 * A075900 A176500 A334099

Adjacent sequences: A055619 A055620 A055621 * A055623 A055624 A055625

KEYWORD

nonn

AUTHOR

William H. Paulsen (wpaulsen(AT)csm.astate.edu), Jun 04 2000

EXTENSIONS

G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009

Additional comments from Robert G. Wilson v, Nov 02 2001

STATUS

approved