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 A104746 #17 Mar 30 2024 07:53:17 %S A104746 1,1,3,1,4,7,1,5,12,15,1,6,17,32,31,1,7,22,49,80,63,1,8,27,66,129,192, %T A104746 127,1,9,32,83,178,321,448,255,1,10,37,100,227,450,769,1024,511,1,11, %U A104746 42,117,276,579,1090,1793,2304,1023,1,12,47,134,325,708,1411,2562,4097,5120,2047,1,13,52,151,374,837,1732,3331,5890,9217,11264,4095 %N A104746 Array T(n,k) read by antidiagonals: T(1,k) = 2^k-1 and recursively T(n,k) = T(n-1,k) + A000337(k-1), n,k >= 1. %C A104746 Generally, row n of the array is the binomial transform for 0, 1, n, 2n-1, 3n-2, 4n-3, ... %F A104746 T(2,k) = A001787(k), binomial transform of 0, 1, 2, 3, 4, 5, 6, ... %F A104746 T(3,k) = A000337(k), binomial transform of 0, 1, 3, 5, 7, 9, 11, ... %F A104746 T(4,k) = A027992(k-1), binomial transform of 0, 1, 4, 7, 10, 13, 16, 19, 22, 25, ... %F A104746 T(5,k) = binomial transform of 0, 1, 5, 9, 13, 17, 21, 25, 29, ... %e A104746 To the first row, add the terms 0, 1, 5, 17, 49, 129, ... as indicated: %e A104746 1, 3, 7, 15, 31, 63, ... %e A104746 0, 1, 5, 17, 49, 129, ... (getting row 2 of the array: %e A104746 1, 4, 12, 32, 80, 192, ... (= A001787, binomial transform for 1,2,3, ...) %e A104746 Repeat the operation, getting the following array T(n,k): %e A104746 1, 3, 7, 15, 31, 63, ... %e A104746 1, 4, 12, 32, 80, 192, ... %e A104746 1, 5, 17, 49, 129, 321, ... %e A104746 1, 6, 22, 66, 178, 450, ... %p A104746 A000337 := proc(n) %p A104746 1+(n-1)*2^n ; %p A104746 end proc: %p A104746 A104746 := proc(n,k) %p A104746 option remember; %p A104746 if n= 1 then %p A104746 2^k-1 ; %p A104746 else %p A104746 procname(n-1,k)+A000337(k-1) ; %p A104746 end if; %p A104746 end proc: %p A104746 for d from 1 to 12 do %p A104746 for k from 1 to d do %p A104746 n := d-k+1 ; %p A104746 printf("%d,",A104746(n,k)) ; %p A104746 end do: %p A104746 end do; # _R. J. Mathar_, Oct 30 2011 %t A104746 A000337[n_] := (n - 1)*2^n + 1; %t A104746 T[1, k_] := 2^k - 1; %t A104746 T[n_, k_] := T[n, k] = T[n - 1, k] + A000337[k - 1]; %t A104746 Table[T[n - k + 1, k], {n, 1, 12}, {k, 1, n}] // Flatten (* _Jean-François Alcover_, Mar 30 2024 *) %Y A104746 Cf. A104747 (antidiagonal sums), A001787, A000337, A027992, A059823. %K A104746 nonn,tabl %O A104746 1,3 %A A104746 _Gary W. Adamson_, Mar 23 2005 %E A104746 Terms corrected by _R. J. Mathar_, Oct 30 2011