cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A195975 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,1,3,4 for x=0,1,2,3,4.

Original entry on oeis.org

9, 43, 67, 133, 244, 519, 1072, 2225, 4456, 9098, 19066, 39689, 82372, 171498, 358146, 748911, 1567225, 3279792, 6866722, 14390098, 30170057, 63261378, 132676528, 278340227, 584041659, 1225661652, 2572438981, 5399619168, 11334969352
Offset: 1

Views

Author

R. H. Hardin Sep 25 2011

Keywords

Comments

Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 3's, every 4 is next to 4 4's
Column 5 of A195978

Examples

			Some solutions for n=4
..1..2..2..1..2....0..0..1..1..0....0..1..1..1..2....1..1..1..0..0
..0..1..1..0..1....0..0..1..1..0....1..1..0..0..1....0..0..1..1..1
..1..1..1..0..1....1..1..1..1..0....1..1..1..1..1....1..1..1..1..1
..1..0..1..1..2....2..1..0..1..1....0..0..1..1..0....2..1..0..0..0
		

Formula

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +11*a(n-3) -6*a(n-4) -36*a(n-5) +90*a(n-6) -142*a(n-7) +197*a(n-8) -46*a(n-9) -183*a(n-10) +478*a(n-11) -942*a(n-12) +792*a(n-13) -498*a(n-14) -210*a(n-15) +1415*a(n-16) -1639*a(n-17) +1834*a(n-18) -709*a(n-19) -862*a(n-20) +1990*a(n-21) -3015*a(n-22) +1957*a(n-23) -374*a(n-24) -1742*a(n-25) +3816*a(n-26) -3839*a(n-27) +2182*a(n-28) -480*a(n-29) -3921*a(n-30) +3721*a(n-31) -4788*a(n-32) +2840*a(n-33) +2416*a(n-34) -577*a(n-35) +7322*a(n-36) -1770*a(n-37) +1322*a(n-38) -1236*a(n-39) -6838*a(n-40) -789*a(n-41) -4538*a(n-42) -89*a(n-43) +3459*a(n-44) +1446*a(n-45) +4611*a(n-46) +1551*a(n-47) -859*a(n-48) -465*a(n-49) -2777*a(n-50) -1070*a(n-51) +363*a(n-52) -79*a(n-53) +1222*a(n-54) -43*a(n-55) -809*a(n-56) -357*a(n-57) -616*a(n-58) +368*a(n-59) +965*a(n-60) +619*a(n-61) +408*a(n-62) -203*a(n-63) -570*a(n-64) -385*a(n-65) -205*a(n-66) +35*a(n-67) +181*a(n-68) +122*a(n-69) +57*a(n-70) +5*a(n-71) -33*a(n-72) -26*a(n-73) -14*a(n-74) -8*a(n-75) -2*a(n-76)