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A112769
Numbers with more than one prime factor and, in the ordered factorization, at least one exponent is less than the previous exponent when read from left to right.
12
12, 20, 24, 28, 40, 44, 45, 48, 52, 56, 60, 63, 68, 72, 76, 80, 84, 88, 90, 92, 96, 99, 104, 112, 116, 117, 120, 124, 126, 132, 135, 136, 140, 144, 148, 152, 153, 156, 160, 164, 168, 171, 172, 175, 176, 180, 184, 188, 189, 192, 198, 200, 204, 207, 208, 212, 220
OFFSET
1,1
COMMENTS
It appears that this sequence lists the integers x such that A085079(n) > n. - Michel Marcus, Jul 30 2015
LINKS
EXAMPLE
90 = 2^1 * 3^2 * 5^1 and 2 > 1, so 90 is in sequence.
MATHEMATICA
mopfQ[n_]:=Module[{e=FactorInteger[n][[All, 2]]}, Length[e]>1&&Min[ Differences[ e]]<0]; Select[Range[300], mopfQ] (* Harvey P. Dale, May 30 2018 *)
PROG
(PARI) isok(n) = {f = factor(n)[, 2]; if (#f > 1, for (k=2, #f, if (f[k] < f[k-1], return (1)); ); ); return (0); } \\ Michel Marcus, Jul 30 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Ray Chandler, Sep 23 2005, based on a suggestion from Leroy Quet
STATUS
approved