A348122 Numbers k such that k and k+1 both have more nonunitary than unitary prime divisors (A348121).

8, 288, 360, 675, 1224, 1331, 1368, 2196, 2400, 2600, 2808, 3024, 5328, 6075, 6859, 9408, 9800, 10647, 11448, 12167, 16128, 17199, 19844, 20448, 21024, 23275, 25920, 26568, 26900, 28899, 29791, 33524, 38024, 38808, 39600, 40400, 41624, 42875, 45324, 46224, 46475

Offset

1,1

Links

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

Example

8 is a term since 8 = 2^3 has one nonunitary prime divisor, 2, and no unitary prime divisors, and 8 + 1 = 9 = 3^2 has one nonunitary prime divisor, 3, and no unitary prime divisors.

Mathematica

q[n_] := 2*Count[(e = FactorInteger[n][[;; , 2]]), 1] < Length[e]; Select[Range[5*10^5], q[#] && q[# + 1] &]

Crossrefs

Subsequence of A348121.

A060355 is a subsequence.

Similar sequence: A348119.

Sequence in context: A136364 A089670 A221612 * A060355 A060859 A187289

Adjacent sequences: A348119 A348120 A348121 * A348123 A348124 A348125

Keyword

nonn

Author

Amiram Eldar, Oct 01 2021

Status

approved