A086291 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A086291

Maximal exponent in prime factorization of 7-smooth numbers.

0, 1, 1, 2, 1, 1, 1, 3, 2, 1, 2, 1, 1, 4, 2, 2, 1, 3, 2, 3, 2, 1, 5, 1, 2, 3, 1, 2, 4, 2, 2, 3, 3, 2, 2, 6, 1, 3, 2, 4, 4, 2, 2, 5, 2, 2, 1, 3, 4, 3, 3, 2, 7, 3, 2, 4, 2, 2, 5, 4, 3, 2, 2, 3, 6, 2, 3, 1, 3, 5, 2, 4, 5, 2, 3, 2, 8, 3, 3, 5, 2, 2, 2, 6, 4, 4, 3, 2, 3, 3, 3, 7, 3, 4, 4, 2, 4, 2, 6, 2

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

OFFSET

1,4

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A051903(A002473(n)).

A086290(n) <= a(n) <= A086289(n).

MATHEMATICA

maxExp[1] = 0; maxExp[n_] := Max @@ Last /@ FactorInteger[n]; maxExp/@Select[Range[500], Max[Transpose[FactorInteger[#]][[1]]] <= 7 &] (* Amiram Eldar, Jan 06 2020 *)

CROSSREFS

Cf. A002473, A051903, A086289, A086290.

Sequence in context: A346009 A344756 A101221 * A262766 A262747 A016442

Adjacent sequences: A086288 A086289 A086290 * A086292 A086293 A086294

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 15 2003

STATUS

approved