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 A223847 #6 Jul 23 2025 04:35:23 %S A223847 296,87616,10804883,664770145,24291817048,594861333098,10609537390768, %T A223847 146233793223364,1627190607796056,15110227641526318, %U A223847 120160497384066604,835281313593693456,5160709016280272028,28729755606226120468 %N A223847 Number of nX5 0..3 arrays with rows and columns unimodal. %C A223847 Column 5 of A223850 %H A223847 R. H. Hardin, <a href="/A223847/b223847.txt">Table of n, a(n) for n = 1..81</a> %F A223847 Empirical: a(n) = (12185409283/15043832793341144432640000000)*n^30 + (76296730104643/884176199373970195454361600000)*n^29 + (1070597323435537/228666258458785395376128000000)*n^28 + (15095976776879/89620324694801252352000000)*n^27 + (80978639299446029/18148115750697253601280000000)*n^26 + (17128733527118137/186134520519971831808000000)*n^25 + (1793728053298859387/1172647479275822540390400000)*n^24 + (1261636802562641833/60135768167990899507200000)*n^23 + (5594512626040336997/23174851369087401984000000)*n^22 + (31544771499812381/13376537586774835200000)*n^21 + (47886425657641284787/2427841571999632588800000)*n^20 + (229975881467092172089/1618561047999755059200000)*n^19 + (9082589031754852696739/10260073516345196544000000)*n^18 + (111240879091929267206971/23256166637049112166400000)*n^17 + (46080377535895002055433/2052014703269039308800000)*n^16 + (5972995162066161572851/65143323913302835200000)*n^15 + (2705387734319931209037779/8305773798946111488000000)*n^14 + (21438489128749966497727/21296855894733619200000)*n^13 + (123748166982394715917397/45739838228461977600000)*n^12 + (281638905229159746619297/44567021863629619200000)*n^11 + (1531541445561308485678126639/119495327371856916480000000)*n^10 + (569764139394721423500017/25290016374996172800000)*n^9 + (12437437033053107961181039/363543985390569984000000)*n^8 + (1801415998853685830112073/40393776154507776000000)*n^7 + (909519212873314420568666851/18379168150301038080000000)*n^6 + (1564096450989494220884147/34035496574631552000000)*n^5 + (108960453802905313513657/3063194691716839680000)*n^4 + (2031598190834852737/90040996229184000)*n^3 + (318817655518333/25794785016000)*n^2 + (1721120935577/388181593800)*n + 1 %e A223847 Some solutions for n=3 %e A223847 ..0..0..0..1..2....0..0..1..2..2....0..0..1..3..1....0..0..0..1..1 %e A223847 ..0..0..1..1..3....0..0..2..3..3....0..0..2..3..1....0..0..3..3..0 %e A223847 ..0..0..0..0..3....0..0..1..3..0....0..2..2..3..1....0..2..3..1..0 %K A223847 nonn %O A223847 1,1 %A A223847 _R. H. Hardin_ Mar 27 2013