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.
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, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76
Offset: 1
Keywords
Examples
(4+6+8+9)/9=3; (9+10+12+14+15)/15=4; (10+12+14+15+16+18+20+21)/21=6; (6+8+9+10+12+14+15+16+18)/18=6; (14+15+16+18+20+21+22+24+25)/25=7; (1+4+6+8+9+10+12+14+15+16+18+20+21+22)/22=8;
Crossrefs
Cf. A018252.
Programs
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Mathematica
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]
Comments