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 A269409 #4 Feb 25 2016 14:38:54 %S A269409 2,3,4,4,9,6,5,16,24,9,6,25,60,63,12,7,36,120,222,159,16,8,49,210,570, %T A269409 804,394,20,9,64,336,1215,2670,2872,957,25,10,81,504,2289,6960,12380, %U A269409 10132,2292,30,11,100,720,3948,15477,39560,56890,35383,5419,36,12,121 %N A269409 T(n,k)=Number of length-n 0..k arrays with no repeated value greater than or equal to the previous repeated value. %C A269409 Table starts %C A269409 ..2.....3......4.......5........6.........7.........8..........9.........10 %C A269409 ..4.....9.....16......25.......36........49........64.........81........100 %C A269409 ..6....24.....60.....120......210.......336.......504........720........990 %C A269409 ..9....63....222.....570.....1215......2289......3948.......6372.......9765 %C A269409 .12...159....804....2670.....6960.....15477.....30744......56124......95940 %C A269409 .16...394...2872...12380....39560....104006....238224.....492312.....939360 %C A269409 .20...957..10132...56890...223320....695135...1837752....4302612....9168780 %C A269409 .25..2292..35383..259445..1253190...4623815..14121282...37478718...89241015 %C A269409 .30..5419.122480.1175355..6995660..30625210.108123624..325487010..866361210 %C A269409 .36.12678.420752.5293671.38870136.202067047.825227424.2819002698.8390905692 %H A269409 R. H. Hardin, <a href="/A269409/b269409.txt">Table of n, a(n) for n = 1..9999</a> %F A269409 Empirical for column k: %F A269409 k=1: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4) %F A269409 k=2: a(n) = 6*a(n-1) -9*a(n-2) -8*a(n-3) +24*a(n-4) -16*a(n-6) %F A269409 k=3: [order 8] %F A269409 k=4: [order 10] %F A269409 k=5: [order 12] %F A269409 k=6: [order 14] %F A269409 k=7: [order 16] %F A269409 Empirical for row n: %F A269409 n=1: a(n) = n + 1 %F A269409 n=2: a(n) = n^2 + 2*n + 1 %F A269409 n=3: a(n) = n^3 + 3*n^2 + 2*n %F A269409 n=4: a(n) = n^4 + 4*n^3 + (7/2)*n^2 + (1/2)*n %F A269409 n=5: a(n) = n^5 + 5*n^4 + (11/2)*n^3 + n^2 - (1/2)*n %F A269409 n=6: a(n) = n^6 + 6*n^5 + 8*n^4 + (5/3)*n^3 - n^2 + (1/3)*n %F A269409 n=7: a(n) = n^7 + 7*n^6 + 11*n^5 + (8/3)*n^4 - (11/6)*n^3 + (1/3)*n^2 - (1/6)*n %e A269409 Some solutions for n=6 k=4 %e A269409 ..3. .2. .1. .0. .1. .3. .1. .0. .0. .1. .0. .2. .4. .3. .0. .4 %e A269409 ..3. .0. .0. .3. .3. .4. .4. .2. .3. .4. .4. .4. .2. .4. .4. .4 %e A269409 ..1. .3. .1. .0. .3. .4. .2. .4. .1. .1. .0. .2. .0. .2. .2. .2 %e A269409 ..0. .4. .4. .3. .0. .0. .1. .0. .2. .4. .2. .4. .2. .4. .1. .4 %e A269409 ..2. .0. .0. .2. .3. .0. .2. .4. .3. .2. .0. .0. .4. .1. .1. .2 %e A269409 ..1. .0. .1. .4. .4. .4. .3. .4. .4. .3. .2. .0. .0. .3. .2. .4 %Y A269409 Column 1 is A002620(n+2). %Y A269409 Column 2 is A267960. %Y A269409 Column 3 is A267928. %Y A269409 Diagonal is A268205. %Y A269409 Row 1 is A000027(n+1). %Y A269409 Row 2 is A000290(n+1). %Y A269409 Row 3 is A007531(n+2). %K A269409 nonn,tabl %O A269409 1,1 %A A269409 _R. H. Hardin_, Feb 25 2016