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

1,1

Comments

Contains A165239 (except 1) as a subsequence.

Links

Table of n, a(n) for n=1..71.

Example

(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;

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]

Crossrefs

Cf. A018252.

Sequence in context: A181590 A243293 A078923 * A350398 A092460 A092459

Adjacent sequences: A165237 A165238 A165239 * A165241 A165242 A165243

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Sep 09 2009

Status

approved