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.
%I A245163 #6 Jul 23 2025 11:29:28 %S A245163 1,1,1,1,1,2,1,1,2,4,1,1,2,4,8,1,1,2,4,9,16,1,1,2,4,9,23,32,1,1,2,4,9, %T A245163 23,64,64,1,1,2,4,9,23,65,186,128,1,1,2,4,9,23,65,199,551,256,1,1,2,4, %U A245163 9,23,65,199,653,1645,512,1,1,2,4,9,23,65,199,654,2275,4926,1024,1,1,2,4,9,23 %N A245163 T(n,k)=Number of length n 0..k arrays with new values introduced in order from both ends. %C A245163 Table starts %C A245163 .....1........1.........1.........1.........1.........1.........1.........1 %C A245163 .....1........1.........1.........1.........1.........1.........1.........1 %C A245163 .....2........2.........2.........2.........2.........2.........2.........2 %C A245163 .....4........4.........4.........4.........4.........4.........4.........4 %C A245163 .....8........9.........9.........9.........9.........9.........9.........9 %C A245163 ....16.......23........23........23........23........23........23........23 %C A245163 ....32.......64........65........65........65........65........65........65 %C A245163 ....64......186.......199.......199.......199.......199.......199.......199 %C A245163 ...128......551.......653.......654.......654.......654.......654.......654 %C A245163 ...256.....1645......2275......2296......2296......2296......2296......2296 %C A245163 ...512.....4926......8313......8568......8569......8569......8569......8569 %C A245163 ..1024....14768.....31439.....33794.....33825.....33825.....33825.....33825 %C A245163 ..2048....44293....121637....140039....140580....140581....140581....140581 %C A245163 ..4096...132867....477307....605869....612890....612933....612933....612933 %C A245163 ..8192...398588...1888721...2718531...2794159...2795181...2795182...2795182 %C A245163 .16384..1195750...7509799..12564289..13280627..13298407..13298464..13298464 %C A245163 .32768..3587235..29940861..59419764..65597882..65851100..65852872..65852873 %C A245163 .65536.10761689.119550419.285878342.335521900.338654554.338694406.338694479 %H A245163 R. H. Hardin, <a href="/A245163/b245163.txt">Table of n, a(n) for n = 1..9999</a> %F A245163 Empirical for column k: %F A245163 k=1: a(n) = 2*a(n-1) for n>2 %F A245163 k=2: a(n) = 5*a(n-1) -7*a(n-2) +3*a(n-3) for n>4 %F A245163 k=3: a(n) = 10*a(n-1) -37*a(n-2) +64*a(n-3) -52*a(n-4) +16*a(n-5) for n>6 %F A245163 k=4: [order 7] for n>8 %F A245163 k=5: [order 9] for n>10 %F A245163 k=6: [order 11] for n>12 %F A245163 k=7: [order 13] for n>14 %e A245163 Some solutions for n=10 k=4 %e A245163 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 %e A245163 ..1....1....1....1....0....1....0....1....0....1....1....0....0....1....1....0 %e A245163 ..1....0....2....0....1....2....1....0....0....2....2....0....1....1....2....1 %e A245163 ..0....1....3....1....2....0....0....2....0....2....1....1....0....1....2....0 %e A245163 ..1....2....0....0....0....1....2....3....0....3....1....2....1....1....2....1 %e A245163 ..0....2....0....2....2....1....0....3....1....1....0....1....2....2....2....0 %e A245163 ..0....1....2....1....2....1....0....2....1....3....2....1....1....1....1....2 %e A245163 ..0....1....1....2....1....1....1....0....1....2....1....1....1....2....1....1 %e A245163 ..1....1....1....1....1....1....0....1....0....1....1....0....1....1....1....1 %e A245163 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 %Y A245163 Column 1 is A000079(n-2) %Y A245163 Column 2 is A164039(n-2) %Y A245163 Diagonal is A007476 %K A245163 nonn,tabl %O A245163 1,6 %A A245163 _R. H. Hardin_, Jul 12 2014