A144147 A positive integer n is included if every exponent in the prime-factorization of n is coprime to n and if the sum of these prime-factorization exponents divides n.

2, 3, 5, 6, 7, 10, 11, 13, 14, 17, 19, 22, 23, 26, 29, 30, 31, 34, 37, 38, 40, 41, 42, 43, 45, 46, 47, 53, 56, 58, 59, 61, 62, 63, 66, 67, 71, 73, 74, 75, 78, 79, 82, 83, 86, 88, 89, 94, 96, 97, 99, 101, 102, 103, 104, 105, 106, 107, 109, 113, 114, 117, 118, 122, 127, 131

Offset

1,1

Comments

All primes are included in the sequence. Any integer = 2*(odd prime) is included in the sequence. This sequence contains those terms in both sequence A074946 and sequence A144146.

Links

Table of n, a(n) for n=1..66.

Example

40 has the prime factorization of 2^3 * 5^1. The exponents are therefore 3 and 1. Both 3 and 1 are coprime to 40. And 3+1 = 4 divides 40. So 40 is included in the sequence.

Crossrefs

A074946, A144146

Sequence in context: A339563 A325396 A326533 * A068422 A085118 A276579

Adjacent sequences: A144144 A144145 A144146 * A144148 A144149 A144150

Keyword

nonn

Author

Leroy Quet, Sep 11 2008

Extensions

Extended by Ray Chandler, Nov 04 2008

Status

approved