A316140 Denominator of the autosequence 2/((n+2)*(n+3)) difference table written by antidiagonals.
3, 6, 6, 10, 15, 10, 15, 30, 30, 15, 21, 105, 70, 105, 21, 28, 84, 140, 140, 84, 28, 36, 126, 252, 315, 252, 126, 36, 45, 180, 420, 630, 630, 420, 180, 45, 55, 495, 660, 1155, 1386, 1155, 660, 495, 55, 66, 330
Offset: 0
Examples
Difference table: 1/3, 1/6, 1/10, 1/15, ... -1/6, -1/15, -1/30, -2/105, ... 1/10, 1/30, 1/70, 1/140, ... -1/15, -2/105, -1/140, -1/315, ... . ... Table starts: 3 6 10 15 21 28 ... 6 15 30 105 84 126 ... 10 30 70 140 252 420 ... 15 105 140 315 630 1155 ... 21 84 252 630 1386 2772 ... ... As a triangle: 3; 6, 6; 10, 15, 10; 15, 30, 30, 15; ...
Links
- OEIS Wiki, Autosequence
Programs
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PARI
tabl(nn) = {nn = 2*nn; m = matrix(nn, nn, n, k, if (n==1, 2/((k+1)*(k+2)))); for (n=2, nn, for (k=1, nn-n +1, m[n, k] = m[n-1, k+1] - m[n-1,k];);); nn = nn/2; matrix(nn, nn, n, k, denominator(m[n,k]));} \\ Michel Marcus, Jul 05 2018