

A201558


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


2



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
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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), 359384 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, JeanLouis Nicolas, and Jonathan Sondow, Dec 03 2011


STATUS

approved



