A386949 Irregular triangle whose n-th row lists the nonzero terms of the n-th column of A386755.

1, 1, 2, 2, 1, 3, 3, 3, 3, 1, 2, 2, 4, 4, 1, 5, 5, 5, 5, 5, 5, 1, 2, 2, 3, 3, 6, 6, 6, 6, 1, 7, 7, 7, 7, 7, 7, 7, 7, 1, 2, 2, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 1, 3, 3, 3, 3, 9, 9, 9, 9, 9, 9, 9, 9, 1, 2, 2, 5, 5, 5, 5, 10, 10, 10, 10, 10, 10, 1, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11

Offset: 1

Author

Michel Marcus, Aug 10 2025

Keywords

• nonn
• tabf

Examples

			Triangle begins:
  1;
  1, 2, 2;
  1, 3, 3, 3, 3;
  1, 2, 2, 4, 4;
  1, 5, 5, 5, 5, 5, 5;
  1, 2, 2, 3, 3, 6, 6, 6, 6;
  1, 7, 7, 7, 7, 7, 7, 7, 7;
  1, 2, 2, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8;
  1, 3, 3, 3, 3, 9, 9, 9, 9, 9, 9, 9, 9;
  1, 2, 2, 5, 5, 5, 5, 10, 10, 10, 10, 10, 10;
  ...
		

Crossrefs

Cf. A386755 (original triangle), A386520 (row sums).

Cf. A027750.

Programs

PARI

orow(n) = my(v=vector(n), m=n); for(k=1, n, my(keepm = m); while(m%k, m--); if (m == 0, keepm=m, v[m] = k; m--); ); v; \\ A386755
nrow(n) = my(ok=1, k=1, last=-1, list=List(), r); while(ok, r=row(k); if ((#r >= n) && r[n], listput(list, r[n])); k++; if (#r>=n, if ((last==n) && (r[n]==0), ok = 0, last = r[n]))); Vec(list);