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.

A214355 Number of 5X5X5 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors.

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%I A214355 #8 Jul 22 2025 23:15:14
%S A214355 1386,80573,1602092,17790765,135538054,790197579,3766437036,
%T A214355 15329961031,54922753470,177082458729,522464071332,1428914669655,
%U A214355 3659885495134,8851607656183,20351858523224,44735107468453,94449669596498
%N A214355 Number of 5X5X5 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors.
%C A214355 Row 5 of A214352
%H A214355 R. H. Hardin, <a href="/A214355/b214355.txt">Table of n, a(n) for n = 1..64</a>
%F A214355 Empirical: a(n) = (250321/163459296000)*n^15 + (57931/605404800)*n^14 + (6130183/2335132800)*n^13 + (5021701/119750400)*n^12 + (12225673/28066500)*n^11 + (33845911/10886400)*n^10 + (1793738911/114307200)*n^9 + (1441174417/25401600)*n^8 + (3431403169/23328000)*n^7 + (2949422359/10886400)*n^6 + (31221432373/89812800)*n^5 + (4515147647/14968800)*n^4 + (193448384201/1135134000)*n^3 + (4506398063/75675600)*n^2 + (2113313/180180)*n + 1
%e A214355 Some solutions for n=2
%e A214355 ......2..........2..........1..........1..........2..........1..........1
%e A214355 .....2.1........1.2........1.2........0.2........2.1........2.0........1.0
%e A214355 ....2.2.1......0.2.1......1.2.2......0.1.2......2.1.0......2.2.0......2.1.0
%e A214355 ...0.2.0.2....0.2.0.2....1.2.2.2....1.0.2.1....2.1.0.1....2.2.0.2....0.2.0.1
%e A214355 ..1.0.2.0.2..0.1.2.0.2..1.2.2.2.1..0.1.0.2.1..2.0.2.0.1..2.2.0.1.2..1.0.2.0.1
%K A214355 nonn
%O A214355 1,1
%A A214355 _R. H. Hardin_ Jul 13 2012