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

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A045796 Numbers m = usigma(sigma(n))/n such that usigma(sigma(n)) is divisible by n. 2
 1, 2, 2, 3, 3, 2, 5, 2, 3, 4, 2, 2, 4, 4, 2, 2, 4, 7, 4, 6, 3, 4, 5, 3, 4, 5, 4, 5, 3, 4, 4, 2, 5, 4, 6, 4, 8, 7, 6, 4, 5, 3, 2, 4, 5, 7, 7, 4, 4, 2, 9, 5, 5, 4, 8, 4, 4, 4, 8, 7, 4, 4, 4, 5, 6, 4, 8, 5, 8, 8, 6, 4, 6, 4, 5, 6, 4, 4, 4, 8, 5, 4, 6, 5, 8, 7, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = m values in A045795. - Donovan Johnson, Mar 12 2013 LINKS Donovan Johnson, Table of n, a(n) for n = 1..100 FORMULA a(n) = usigma(sigma(A045795(n)))/A045795(n). MAPLE A034448 := proc(n) local ans, i: ans := 1: for i from 1 to nops(ifactors(n)[ 2 ]) do ans := ans*(1+ifactors(n)[2][i][1]^ifactors(n)[2][i][2]): od: RETURN(ans) end: isA045795 := proc(n) if A034448(numtheory[sigma](n)) mod n = 0 then A034448(numtheory[sigma](n))/n ; else -1 ; fi ; end: A045796 := proc() local n, a : n := 2: while true do a := isA045795(n) ; if a>=0 then printf("%d, ", a) ; fi ; n := n+1: od : end: A045796() ; # R. J. Mathar, Jun 26 2007 CROSSREFS Cf. A045795, A034448. Sequence in context: A167618 A211707 A303363 * A127684 A036012 A084401 Adjacent sequences:  A045793 A045794 A045795 * A045797 A045798 A045799 KEYWORD nonn AUTHOR EXTENSIONS Corrected and extended by R. J. Mathar, Jun 26 2007 Missing first term added and offset corrected by Donovan Johnson, Mar 12 2013 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 January 22 16:37 EST 2020. Contains 331152 sequences. (Running on oeis4.)