# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a194933 Showing 1-1 of 1 %I A194933 #9 May 05 2018 20:42:29 %S A194933 1024,5873,12474,19379,26316,33255,40194,47133,54072,61011,67950, %T A194933 74889,81828,88767,95706,102645,109584,116523,123462,130401,137340, %U A194933 144279,151218,158157,165096,172035,178974,185913,192852,199791,206730,213669 %N A194933 Number of lower triangles of a 4 X 4 0..n array with no element differing from any of its horizontal or vertical neighbors by more than one. %C A194933 Row 4 of A194931. %H A194933 R. H. Hardin, Table of n, a(n) for n = 1..200 %F A194933 Empirical: a(n) = 6939*n - 8379 for n>4. %F A194933 Empirical g.f.: x*(1024 + 3825*x + 1752*x^2 + 304*x^3 + 32*x^4 + 2*x^5) / (1 - x)^2. - _Colin Barker_, May 05 2018 %e A194933 Some solutions for n=4: %e A194933 ..2........0........1........1........2........2........0........2 %e A194933 ..1.2......0.1......0.0......2.3......1.2......1.0......0.0......2.1 %e A194933 ..2.3.4....0.1.1....1.1.1....3.3.3....1.2.2....0.0.1....1.0.1....2.2.2 %e A194933 ..3.3.3.4..0.0.1.1..0.1.1.2..3.2.2.2..0.1.2.1..0.1.2.2..1.0.0.0..2.2.2.3 %Y A194933 Cf. A194931. %K A194933 nonn %O A194933 1,1 %A A194933 _R. H. Hardin_, Sep 05 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE