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 A191709 #7 Oct 17 2017 20:49:00 %S A191709 1,3,2,5,4,7,8,6,10,12,11,9,14,16,17,15,13,19,21,23,22,20,18,25,28,30, %T A191709 29,27,26,24,33,36,39,38,35,32,34,31,43,46,50,49,45,41,37,44,40,55,59, %U A191709 64,63,58,53,48,42,56,51,70,75,81,80,74,68,61,54,47,71 %N A191709 Dispersion of A047202, (numbers >1 and congruent to 0, 1, 3, or 4 mod 5), by antidiagonals. %C A191709 For a background discussion of dispersions and their fractal sequences, see A191426. For dispersions of congruence sequences mod 3 or mod 4, see A191655, A191663, A191667. %C A191709 ... %C A191709 Each of the sequences (5n, n>1), (5n+1, n>1), (5n+2, n>=0), (5n+3, n>=0), (5n+4, n>=0), generates a dispersion. Each complement (beginning with its first term >1) also generates a dispersion. The ten sequences and dispersions are listed here: %C A191709 ... %C A191709 A191702=dispersion of A008587 (5k, k>=1) %C A191709 A191703=dispersion of A016861 (5k+1, k>=1) %C A191709 A191704=dispersion of A016873 (5k+2, k>=0) %C A191709 A191705=dispersion of A016885 (5k+3, k>=0) %C A191709 A191706=dispersion of A016897 (5k+4, k>=0) %C A191709 A191707=dispersion of A047201 (1, 2, 3, 4 mod 5 and >1) %C A191709 A191708=dispersion of A047202 (0, 2, 3, 4 mod 5 and >1) %C A191709 A191709=dispersion of A047207 (0, 1, 3, 4 mod 5 and >1) %C A191709 A191710=dispersion of A032763 (0, 1, 2, 4 mod 5 and >1) %C A191709 A191711=dispersion of A001068 (0, 1, 2, 3 mod 5 and >1) %C A191709 ... %C A191709 EXCEPT for at most 2 initial terms (so that column 1 always starts with 1): %C A191709 A191702 has 1st col A047201, all else A008587 %C A191709 A191703 has 1st col A047202, all else A016861 %C A191709 A191704 has 1st col A047207, all else A016873 %C A191709 A191705 has 1st col A032763, all else A016885 %C A191709 A191706 has 1st col A001068, all else A016897 %C A191709 A191707 has 1st col A008587, all else A047201 %C A191709 A191708 has 1st col A042968, all else A047203 %C A191709 A191709 has 1st col A042968, all else A047207 %C A191709 A191710 has 1st col A042968, all else A032763 %C A191709 A191711 has 1st col A042968, all else A001068 %C A191709 ... %C A191709 Regarding the dispersions A191670-A191673, there is a formula for sequences of the type "(a or b or c or d mod m)", (as in the relevant Mathematica programs): %C A191709 ... %C A191709 If f(n)=(n mod 3), then (a,b,c,d,a,b,c,d,a,b,c,d,...) is given by a*f(n+3)+b*f(n+2)+c*f(n+1)+d*f(n); so that for n>=1, "(a, b, c, d mod m)" is given by %C A191709 a*f(n+3)+b*f(n+2)+c*f(n+1)+d*f(n)+m*floor((n-1)/4)). %H A191709 Ivan Neretin, <a href="/A191709/b191709.txt">Table of n, a(n) for n = 1..5050</a> (first 100 antidiagonals, flattened) %e A191709 Northwest corner: %e A191709 1....3....5....8....11 %e A191709 2....4....6....9....13 %e A191709 7....10...14...19...25 %e A191709 12...16...21...28...36 %e A191709 17...23...30...39...50 %e A191709 22...29...38...49...63 %t A191709 (* Program generates the dispersion array T of the increasing sequence f[n] *) %t A191709 r = 40; r1 = 12; c = 40; c1 = 12; %t A191709 a=3; b=4; c2=5; d=6; m[n_]:=If[Mod[n,4]==0,1,0]; %t A191709 f[n_]:=a*m[n+3]+b*m[n+2]+c2*m[n+1]+d*m[n]+5*Floor[(n-1)/4] %t A191709 Table[f[n], {n, 1, 30}] (* A047207 *) %t A191709 mex[list_] := NestWhile[#1 + 1 &, 1, Union[list][[#1]] <= #1 &, 1, Length[Union[list]]] %t A191709 rows = {NestList[f, 1, c]}; %t A191709 Do[rows = Append[rows, NestList[f, mex[Flatten[rows]], r]], {r}]; %t A191709 t[i_, j_] := rows[[i, j]]; %t A191709 TableForm[Table[t[i, j], {i, 1, 10}, {j, 1, 10}]] (* A191709 *) %t A191709 Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191709 *) %Y A191709 Cf. A047207, A016873, A191704, A191426. %K A191709 nonn,tabl %O A191709 1,2 %A A191709 _Clark Kimberling_, Jun 12 2011