A142593 Irregular triangle read by rows: row n gives successive exponents in prime factorization of A141900(n).

1, 2, 1, 3, 1, 4, 1, 1, 5, 1, 1, 6, 1, 1, 1, 7, 1, 1, 1, 8, 3, 1, 1, 9, 3, 1, 1, 10, 3, 1, 1, 1, 11, 3, 1, 1, 1, 12, 3, 1, 1, 1, 1, 13, 3, 1, 1, 1, 1, 14, 3, 1, 1, 1, 1, 15, 3, 1, 1, 1, 1, 16, 3, 1, 1, 1, 1, 1, 17, 3, 1, 1, 1, 1, 1, 18, 3, 1, 1, 1, 1, 1, 1, 19, 3, 1, 1, 1, 1, 1, 1, 20, 3, 1, 1

Offset: 1

Author

David Applegate, Tim Kunisky (tkunisky(AT)gmail.com), Gerry Manoim (gerrymanoim(AT)gmail.com) and N. J. A. Sloane, Sep 25 2008

Keywords

• nonn
• tabf

Examples

			Triangle begins:
1
2 1
3 1
4 1 1
5 1 1
6 1 1 1
7 1 1 1
8 3 1 1
9 3 1 1
10 3 1 1 1
11 3 1 1 1
12 3 1 1 1 1
Row 8 = [8,3,1,1] because A141900(8) = 2^8*3^3*5*7 = 241920.
		

Links

• David Applegate, Maple program which generates this triangle [The command hpat(n); returns the n-th row in an encoded form.]
• N. J. A. Sloane, Rows 1 through 50 of the triangle

Crossrefs

Cf. A141586, A141900, A142594.