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 A165240 Integers of the form (a+b+c+..+z)/z where (a,b,c,..,z) is a list of 2 or more distinct consecutive nonprimes. 2

%I

%S 3,4,6,7,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24,25,26,27,28,29,

%T 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,

%U 53,54,55,56,57,58,59,60,61,62,63,64,66,67,68,69,70,71,72,73,74,75,76

%N Integers of the form (a+b+c+..+z)/z where (a,b,c,..,z) is a list of 2 or more distinct consecutive nonprimes.

%C Contains A165239 (except 1) as a subsequence.

%e (4+6+8+9)/9=3;

%e (9+10+12+14+15)/15=4;

%e (10+12+14+15+16+18+20+21)/21=6;

%e (6+8+9+10+12+14+15+16+18)/18=6;

%e (14+15+16+18+20+21+22+24+25)/25=7;

%e (1+4+6+8+9+10+12+14+15+16+18+20+21+22)/22=8;

%t lst={};Do[a=0;If[ !PrimeQ[q],Do[If[ !PrimeQ[n],m=n;a+=m;e=a/n;If[IntegerQ[e]&&a!=n,If[e<83,AppendTo[lst,e],Break[]]]],{n,q,3*6!}]],{q,2*6!}];lst=Take[Union@lst,77]

%Y Cf. A018252.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Sep 09 2009

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Last modified January 27 04:57 EST 2020. Contains 331291 sequences. (Running on oeis4.)