The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A239851 Number of n X 1 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4. 10
 2, 2, 4, 6, 8, 14, 20, 30, 48, 70, 108, 166, 248, 382, 580, 878, 1344, 2038, 3100, 4726, 7176, 10926, 16628, 25278, 38480, 58534, 89036, 135494, 206104, 313566, 477092, 725774, 1104224, 1679958, 2555772, 3888406, 5915688, 8999950, 13692500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A239858. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = a(n-2) +2*a(n-3). Empirical g.f.: 2*x*(1 + x + x^2) / (1 - x^2 - 2*x^3). - Colin Barker, Feb 18 2018 EXAMPLE All solutions for n=4: ..3....3....2....2....2....3 ..2....2....3....3....3....2 ..3....3....3....2....3....2 ..2....3....3....2....2....2 CROSSREFS Sequence in context: A266949 A255710 A329137 * A153958 A216214 A269298 Adjacent sequences: A239848 A239849 A239850 * A239852 A239853 A239854 KEYWORD nonn AUTHOR R. H. Hardin, Mar 28 2014 STATUS approved

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

Last modified March 1 09:59 EST 2024. Contains 370432 sequences. (Running on oeis4.)