A212178 Number of exponents >= 2 in canonical prime factorization of A025487(n) (first integer of each prime signature).

0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 0, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 3, 1, 1, 2, 2, 2, 2, 2, 1, 1, 2, 3, 1, 1, 2, 2, 0, 2, 2, 2, 1, 1, 2, 3, 1, 1, 2, 2, 1, 2, 2, 3, 2, 1, 3, 2, 1, 2, 3, 2, 1, 2, 1, 2, 2, 1, 2, 2, 3, 2, 1

Offset: 1

Author

Matthew Vandermast, Jun 04 2012

Keywords

• nonn

Comments

Length of row n of A212175 equals a(n) if a(n) is positive, 1 otherwise.

Examples

			The canonical prime factorization of 24 (2^3*3) has 1 exponent that equals or exceeds 2. Since 24 = A025487(8), a(8) = 1.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Will Nicholes, Prime Signatures
• Index entries for sequences related to prime signature

Crossrefs

Cf. A025487, A212172.

Formula

a(n) = A056170(A025487(n)).