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A007780 Losing initial configurations in 2-hole Tchuka Ruma. 2
1, 2, 3, 6, 9, 11, 18, 20, 27, 30, 54, 81, 162, 168, 243, 486, 729, 1458, 2187, 4374, 6561, 13122, 19683, 39366, 59049, 118098, 177147, 354294, 531441, 1062882, 1594323, 3188646, 4782969, 9565938, 14348907, 28697814, 43046721, 86093442 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The 2-hole Tchuka Ruma game cannot be won for the initial seeds 3^i (i>=1) or 2*3^i (i>=0). Though a sufficient condition, this is not necessary, as can be seen from the terms a(6)=11, a(8)=20, a(10)=30 and a(14)=168. - Pab Ter (pabrlos2(AT)yahoo.com), Nov 08 2005

If any further sporadic term exists, then it exceeds 6973568802. - Sean A. Irvine, Jan 25 2018

LINKS

Sean A. Irvine, Table of n, a(n) for n = 1..46

Paul J. Campbell, and Darrah P. Chavey, Tchuka Ruma Solitaire, The UMAP Journal 16(4) (1995), 343-365.

FORMULA

Conjectures from Colin Barker, Jan 25 2018: (Start)

G.f.: x*(1 + 2*x - 7*x^5 - 9*x^6 - 13*x^7 - 27*x^8 - 30*x^9 - 27*x^10 - 9*x^11 - 75*x^13 - 243*x^14 - 18*x^15) / (1 - 3*x^2).

a(n) = 3*a(n-2) for n>2.

(End)

CROSSREFS

Sequence in context: A176189 A057127 A224449 * A018537 A018331 A032704

Adjacent sequences:  A007777 A007778 A007779 * A007781 A007782 A007783

KEYWORD

nonn

AUTHOR

Darrah Chavey

EXTENSIONS

More terms from Pab Ter (pabrlos2(AT)yahoo.com), Nov 08 2005

More terms from Sean A. Irvine, Jan 25 2018

STATUS

approved

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Last modified August 9 14:23 EDT 2020. Contains 336323 sequences. (Running on oeis4.)