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 A194845 #5 Mar 30 2012 18:57:44 %S A194845 1,2,3,4,5,6,7,8,9,10,12,13,14,15,11,17,19,20,21,16,18,23,25,27,28,22, %T A194845 24,26,30,32,34,36,29,31,33,35,39,41,43,45,38,40,42,44,37,48,51,53,55, %U A194845 47,50,52,54,46,49,58,61,64,66,57,60,63,65,56,59,62,69,72,75 %N A194845 Rectangular array, by antidiagonals: row n gives the positions of n in the fractal sequence A194844; an interspersion. %C A194845 See A194832 and A194844. %e A194845 Northwest corner: %e A194845 1...2...4...7...12..17 %e A194845 3...5...8...13..19..25 %e A194845 6...9...14..20..27..34 %e A194845 10..15..21..28..36..45 %e A194845 11..16..22..29..38..47 %e A194845 18..24..31..40..50..60 %t A194845 r = Sqrt[5]; %t A194845 t[n_] := Table[FractionalPart[k*r], {k, 1, n}]; %t A194845 f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]] (* A194844 *) %t A194845 TableForm[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 15}]] %t A194845 row[n_] := Position[f, n]; %t A194845 u = TableForm[Table[row[n], {n, 1, 20}]] %t A194845 g[n_, k_] := Part[row[n], k]; %t A194845 p = Flatten[Table[g[k, n - k + 1], {n, 1, 13}, %t A194845 {k, 1, n}]] (* A194845 *) %t A194845 q[n_] := Position[p, n]; Flatten[ %t A194845 Table[q[n], {n, 1, 80}]] (* A194846 *) %Y A194845 Cf. A194832, A194844, A194846. %K A194845 nonn,tabl %O A194845 1,2 %A A194845 _Clark Kimberling_, Sep 04 2011