The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A267912 Number of 1 X n 0..2 arrays with every repeated value in every row unequal to the previous repeated value, and in every column equal to the previous repeated value, and new values introduced in row-major sequential order. 3
 1, 2, 4, 11, 29, 77, 201, 525, 1361, 3525, 9097, 23453, 60353, 155189, 398649, 1023501, 2626289, 6736677, 17274601, 44286845, 113516321, 290925845, 745515417, 1910267373, 4894426193, 12539689989, 32125783369, 82301320541, 210838008449 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row 1 of A267911. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-1) + 2*a(n-2) - 8*a(n-3) for n>5. Conjectures from Colin Barker, Feb 25 2018: (Start) G.f.: x*(1 - x - 4*x^2 + 3*x^3 + 4*x^4) / ((1 - 2*x)*(1 - x - 4*x^2)). a(n) = (1/17)*2^(-5-n)*(-17*4^(1+n) + (85-19*sqrt(17))*(1-sqrt(17))^n + (1+sqrt(17))^n*(85+19*sqrt(17))) for n>2. (End) EXAMPLE Some solutions for n=8: ..0..1..1..2..0..1..2..0....0..1..2..0..2..0..1..0....0..1..2..0..0..1..0..2 CROSSREFS Cf. A267911. Sequence in context: A148139 A061860 A093960 * A118311 A132836 A148140 Adjacent sequences:  A267909 A267910 A267911 * A267913 A267914 A267915 KEYWORD nonn AUTHOR R. H. Hardin, Jan 22 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 4 19:15 EDT 2020. Contains 336202 sequences. (Running on oeis4.)