A201558 Number of GA1 numbers A197638 with n >= 3 prime factors counted with multiplicity.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 2, 1, 1, 2, 4, 1, 2, 3, 7, 7, 7, 1, 4, 7

Offset

3,11

Comments

The number of GA1 numbers with one (resp., two) prime factors is zero (resp., infinity).

GA1 numbers with at least three prime factors are called "proper" - see A201557.

For a(n), see Section 6.2 of "On SA, CA, and GA numbers", and below "kmax" in "Table of proper GA1 numbers up to 10^60".

Links

Table of n, a(n) for n=3..28.

G. Caveney, J.-L. Nicolas, and J. Sondow, Robin's theorem, primes, and a new elementary reformulation of the Riemann Hypothesis, Integers 11 (2011), article A33.

G. Caveney, J.-L. Nicolas and J. Sondow, On SA, CA, and GA numbers, Ramanujan J., 29 (2012), 359-384 and arXiv:1112.6010.

J.-L. Nicolas, Computation of GA1 numbers, 2011.

J.-L. Nicolas, Table of proper GA1 numbers up to 10^60, 2011.

Example

183783600 = 2^4 * 3^3 * 5^2 * 7 * 11 * 13 * 17 is the first of the a(13) = 2 GA1 numbers with 4 + 3 + 2 + 1 + 1 + 1 + 1 = 13 prime factors.

Maple

See "Computation of GA1 numbers".

Crossrefs

Cf. A067698, A197638, A197639, A201557.

Sequence in context: A279315 A303293 A344637 * A052285 A046858 A225812

Adjacent sequences: A201555 A201556 A201557 * A201559 A201560 A201561

Keyword

nonn

Author

Geoffrey Caveney, Jean-Louis Nicolas, and Jonathan Sondow, Dec 03 2011

Status

approved