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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A062822 Sum of divisors of the squarefree numbers: sigma(A005117(n)). 5
 1, 3, 4, 6, 12, 8, 18, 12, 14, 24, 24, 18, 20, 32, 36, 24, 42, 30, 72, 32, 48, 54, 48, 38, 60, 56, 42, 96, 44, 72, 48, 72, 54, 72, 80, 90, 60, 62, 96, 84, 144, 68, 96, 144, 72, 74, 114, 96, 168, 80, 126, 84, 108, 132, 120, 90, 112, 128, 144, 120, 98, 102, 216, 104, 192 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = Product_{k=1..A001221(n)} (A265668(n,k) + 1). - Reinhard Zumkeller, Dec 13 2015 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 MATHEMATICA DivisorSigma[1, #]&/@Select[Range[150], SquareFreeQ] (* Harvey P. Dale, May 18 2014 *) PROG (PARI) j=[]; for(n=1, 200, if(issquarefree(n), j=concat(j, sigma(n)))); j (Haskell) a062822 1 = 1 a062822 n = product \$ map (+ 1) \$ a265668_row n -- Reinhard Zumkeller, Dec 13 2015 CROSSREFS Cf. A000203, A005117, A265668, A001221. Sequence in context: A002090 A199970 A283738 * A175894 A175029 A113728 Adjacent sequences:  A062819 A062820 A062821 * A062823 A062824 A062825 KEYWORD nonn AUTHOR Jason Earls, Jul 20 2001 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 April 13 22:18 EDT 2021. Contains 342941 sequences. (Running on oeis4.)