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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 7 18:19 EST 2021. Contains 349585 sequences. (Running on oeis4.)