The OEIS is supported by the many generous donors to the OEIS 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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A078713 Sum of squares of the distances between successive divisors of n. 2
 0, 1, 4, 5, 16, 11, 36, 21, 40, 35, 100, 43, 144, 75, 108, 85, 256, 101, 324, 131, 216, 203, 484, 171, 416, 291, 364, 259, 784, 273, 900, 341, 552, 515, 804, 385, 1296, 651, 780, 519, 1600, 551, 1764, 659, 960, 971, 2116, 683, 1800, 885, 1356, 931, 2704, 911, 1988 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE The divisors of 10 are 1, 2, 5, 10 and the sum of the squares of the distances between successive divisors = (2-1)^2 + (5-2)^2 + (10-5)^2 = 35. Hence a(10) = 35. MATHEMATICA f[n_] := Module[{d, l, s, i}, d = Divisors[n]; l = Length[d]; s = 0; For[i = 1, i < l, i++, s = s + (d[[i + 1]] - d[[i]])^2]; s]; Table[f[n], {n, 1, 100}] Table[Total[Differences[Divisors[n]]^2], {n, 60}] (* Harvey P. Dale, Apr 10 2018 *) CROSSREFS Sequence in context: A244643 A085768 A166304 * A175263 A000695 A081345 Adjacent sequences: A078710 A078711 A078712 * A078714 A078715 A078716 KEYWORD nonn AUTHOR Joseph L. Pe, Dec 19 2002 STATUS approved

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

Last modified December 8 01:12 EST 2022. Contains 358672 sequences. (Running on oeis4.)