A073915 Triangle read by rows in which the n-th row contains the first n numbers with n divisors.

1, 2, 3, 4, 9, 25, 6, 8, 10, 14, 16, 81, 625, 2401, 14641, 12, 18, 20, 28, 32, 44, 64, 729, 15625, 117649, 1771561, 4826809, 24137569, 24, 30, 40, 42, 54, 56, 66, 70, 36, 100, 196, 225, 256, 441, 484, 676, 1089, 48, 80, 112, 162, 176, 208, 272, 304, 368, 405

Offset: 1

Author

Amarnath Murthy, Aug 18 2002

Keywords

• nonn
• tabl

Comments

The first row contains the 1. The 2nd row contains the beginning of A000040. The 3rd contains the beginning of A001248, the 4th through 7th A030513 to A030516. The 8th through 20th rows come from A030626 to A030638. - R. J. Mathar, Mar 23 2007

Examples

			1;
2,3;
4,9,25;
6,8,10,14;
16,81,625,2401,14641;
...
		

Links

• T. D. Noe, Rows n = 1..100 of triangle, flattened

Crossrefs

Cf. A073916.

Programs

Mathematica

d = Table[Length[Divisors[n]], {n, 2000}]; t = {}; n = 0; ok = True; While[ok, n++; If[PrimeQ[n], AppendTo[t, Prime[Range[n]]^(n - 1)], c = Flatten[Position[d, n, 1, n]]; If[Length[c] >= n, AppendTo[t, c], ok = False]]]; Flatten[t] (* T. D. Noe, Jun 23 2013 *)

Extensions

Corrected and extended by Sascha Kurz, Jan 28 2003