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 A124459 #9 Aug 12 2015 02:16:07 %S A124459 2,3,2,3,5,2,3,8,7,2,3,11,15,9,2,3,14,26,24,11,2,3,17,40,50,35,13,2,3, %T A124459 20,57,90,85,48,15,2,3,23,77,147,175,133,63,17,2,3,26,100,224,322,308, %U A124459 196,80,19,2,3,29,126,324,546,630,504,276,99,21,2,3,32,155,450,870,1176 %N A124459 Square array resulting from the bisection of array A124458. (The other array is A093560.) %C A124459 Apparently the same as A029618 if the first term is ignored. - _R. J. Mathar_, Jun 18 2008 %e A124459 Given the square array %e A124459 1 2 3 3 3 3 3 3 3 3 %e A124459 1 2 4 5 7 8 10 11 13 %e A124459 1 2 5 7 12 15 22 26 %e A124459 1 2 6 9 18 24 40 %e A124459 1 2 7 11 25 35 %e A124459 1 2 8 13 33 (Table A124458) %e A124459 1 2 9 15 %e A124459 1 2 10 %e A124459 1 2 %e A124459 1 %e A124459 Omit these odd columns: %e A124459 1 3 3 3 3 3 3 3 3 3 3 %e A124459 1 4 7 10 13 16 19 22 25 28 %e A124459 1 5 12 22 35 51 70 92 117 %e A124459 1 6 18 40 75 126 196 288 %e A124459 1 7 25 65 140 266 462 %e A124459 1 8 33 98 238 504 %e A124459 1 9 42 140 378 %e A124459 1 10 52 192 (Table A093560) %e A124459 1 11 63 %e A124459 1 12 %e A124459 1 %e A124459 which yields the square array A124459 %p A124459 Reppasc := proc(n,k) binomial(n+floor(k/2),n) ; end: A124458 := proc(n,k) add(Reppasc(n,i), i=max(0,k-3)..k-1) ; end: A124459 := proc(n,k) A124458(n,2*k) ; end: for d from 1 to 19 do for k from d to 1 by -1 do n := d-k ; printf("%d,",A124459(n,k)) ; od: od: # _R. J. Mathar_, Jun 18 2008 %Y A124459 Cf. A084215 (antidiagonal sums). %K A124459 easy,nonn,tabl %O A124459 1,1 %A A124459 _Alford Arnold_, Nov 09 2006 %E A124459 More terms from _R. J. Mathar_, Jun 18 2008