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

1,2

Links

Table of n, a(n) for n=1..95.

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

Example

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.

Crossrefs

Cf. A141586, A141900, A142594.

Sequence in context: A195838 A195837 A123539 * A360285 A226248 A102547

Adjacent sequences: A142590 A142591 A142592 * A142594 A142595 A142596

Keyword

nonn,tabf

Author

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

Status

approved