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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A195957 Number of nX3 0..4 arrays with each element equal to the number its horizontal and vertical neighbors unequal to itself 1
 2, 6, 10, 16, 21, 44, 82, 144, 273, 531, 1032, 1960, 3805, 7446, 14505, 28254, 55311, 108511, 212645, 417039, 819145, 1609692, 3163058, 6217976, 12229218, 24055201, 47320658, 93104592, 183213156, 360551489, 709578685, 1396577604, 2748853048 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A195962 LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = 2*a(n-2) +5*a(n-3) +5*a(n-4) -4*a(n-5) -15*a(n-6) -14*a(n-7) -a(n-8) +10*a(n-9) +2*a(n-10) -16*a(n-11) -15*a(n-12) +9*a(n-13) +29*a(n-14) +20*a(n-15) -2*a(n-16) -10*a(n-17) -4*a(n-18) EXAMPLE Some solutions for n=5 ..1..1..1....1..1..1....1..1..1....2..3..2....2..3..2....2..3..2....2..1..1 ..2..2..2....2..3..2....3..4..3....3..4..3....3..4..3....1..1..1....1..1..3 ..3..4..3....2..3..2....2..2..2....2..2..2....2..2..2....1..1..1....1..1..1 ..2..2..2....3..4..3....3..4..3....3..4..3....3..4..3....3..4..3....3..4..1 ..1..1..1....1..1..1....1..1..1....2..3..2....1..1..1....1..1..1....2..3..1 CROSSREFS Sequence in context: A124198 A032426 A220453 * A294013 A183575 A096184 Adjacent sequences:  A195954 A195955 A195956 * A195958 A195959 A195960 KEYWORD nonn AUTHOR R. H. Hardin Sep 25 2011 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 December 8 05:15 EST 2021. Contains 349590 sequences. (Running on oeis4.)