A238946 - OEIS

A238946

Maximal level size of arcs in divisor lattice D(n).

0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 2, 1, 1, 3, 1, 3, 2, 2, 1, 3, 1, 2, 1, 3, 1, 6, 1, 1, 2, 2, 2, 4, 1, 2, 2, 3, 1, 6, 1, 3, 3, 2, 1, 3, 1, 3, 2, 3, 1, 3, 2, 3, 2, 2, 1, 7, 1, 2, 3, 1, 2, 6, 1, 3, 2, 6, 1, 5, 1, 2, 3, 3, 2, 6, 1, 3, 1, 2

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

OFFSET

1,6

COMMENTS

A divisor d of n has level given by bigomega(d) and in-degree given by omega(d). The number of arcs on a level is the sum of the in-degrees of all divisors on the level. - Andrew Howroyd, Mar 28 2020

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1000 (terms 1..200 from Sung-Hyuk Cha)

S.-H. Cha, E. G. DuCasse, and L. V. Quintas, Graph Invariants Based on the Divides Relation and Ordered by Prime Signatures, arXiv:1405.5283 [math.NT], 2014.

PROG

(PARI) a(n)={if(n==1, 0, my(v=vector(bigomega(n))); fordiv(n, d, if(d>1, v[bigomega(d)] += omega(d))); vecmax(v))} \\ Andrew Howroyd, Mar 28 2020

CROSSREFS

Cf. A001221 (omega), A001222 (bigomega), A062799, A096825, A238955, A238968.

Sequence in context: A372772 A324191 A373957 * A351414 A349056 A326516

Adjacent sequences: A238943 A238944 A238945 * A238947 A238948 A238949

KEYWORD

nonn

AUTHOR

Sung-Hyuk Cha, Mar 07 2014

EXTENSIONS

a(1) corrected by Andrew Howroyd, Mar 28 2020

STATUS

approved