The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A330580 Composite numbers n that divide the sum of all composite numbers <= n. 1
 4, 9, 604, 1849, 7123, 29588, 71056, 317238, 945414, 1347895, 3567705, 4624025, 8518502, 1523051853, 4353560959, 7537630621, 24916885136, 41483524658, 513849020166, 1021228997529, 1137756574012, 1185967711155, 1581191501535, 1705826324526 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA a(n) = A002808(A330579(n)). PROG (PARI) s=0; k=0; forcomposite (c=4, oo, k++; s+=c; if (s%c==0, print1 (c", "))) CROSSREFS Cf. A002808, A007506 (prime variant), A330579. Sequence in context: A068708 A063248 A027522 * A254959 A028869 A179935 Adjacent sequences:  A330577 A330578 A330579 * A330581 A330582 A330583 KEYWORD nonn,more AUTHOR Rémy Sigrist, Dec 18 2019 EXTENSIONS a(15)-a(24) from Giovanni Resta, Dec 20 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 3 12:16 EST 2021. Contains 349462 sequences. (Running on oeis4.)