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 A121306 #7 Jul 03 2016 00:15:22 %S A121306 2,2,3,2,5,4,2,7,9,5,2,9,16,14,6,2,11,25,30,20,7,2,13,36,55,50,27,8,2, %T A121306 15,49,91,105,77,35,9,2,17,64,140,196,182,112,44,10,19,81,204,336,378, %U A121306 294,156,54,100,285,540,714,672,450,210,385,825,1254,1386,1122 %N A121306 Array read by antidiagonals: a(m,n) = a(m,n-1)+a(m-1,n) but with initialization values a(0,0)=0, a(m>=1,0)=1, a(0,1)=1, a(0,n>1)=0. %C A121306 For a(1,0)=1, a(m>1,0)=0 and a(0,n>=0)=0 one gets Pascal's triangle A007318. %F A121306 a(m,n) = a(m,n-1)+a(m-1,n), a(0,0)=0, a(m>=1,0)=1, a(0,1)=1, a(0,n>1)=0. %e A121306 Array begins %e A121306 2 2 2 2 2 2 2 2 2 ... %e A121306 3 5 7 9 11 13 15 17 19 ... %e A121306 4 9 16 25 36 49 64 81 100 ... %e A121306 5 14 30 55 91 140 204 285 385 ... %e A121306 6 20 50 105 196 336 540 825 1210 ... %e A121306 7 27 77 182 378 714 1254 2079 3289 ... %o A121306 (Excel) =Z(-1)S+ZS(-1). The very first row (not included into the table) contains the initialization values: a(0,1)=1, a(0,n>=2)=0. The very first column (not included into the table) contains the initialization values: a(m>=1,0)=1. The value a(0,0)=0 does not enter into the table. %Y A121306 The first nine rows are: A006527, A005408, A000290, A000330, A002415, A005585, A040977, A050486, A053347. %Y A121306 The initial columns are: A000027, A000096, A005581, A005582, A005583, A005584. %Y A121306 Cf. A119800, A007318, A006527, A005408, A000290, A000330, A002415, A005585, A040977, A050486, A053347, A000027, A000096, A005581, A005582, A005583, A005584. %K A121306 nonn,tabl %O A121306 0,1 %A A121306 _Thomas Wieder_, Aug 04 2006, Aug 06 2006 %E A121306 Edited by _N. J. A. Sloane_, Sep 15 2006