This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A160907 Sum of the number of prime divisors including repetitions between n^2 and (n+1)^2. 1
 4, 11, 17, 23, 30, 34, 42, 50, 54, 58, 67, 73, 78, 85, 95, 99, 103, 111, 117, 124, 128, 140, 143, 151, 157, 163, 174, 174, 183, 187, 197, 210, 207, 217, 222, 229, 235, 244, 251, 256, 261, 270, 276, 285, 293, 298, 304, 311, 318, 327, 331, 334, 347, 352, 362, 366 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE Between 1^2 and 2^2 we have 0,1,1,2 which sum to 4, so a(1)=4. Between 2^2 and 3^2 we have 2,1,2,1,3,2 which sum to 11, so a(2)=11. MATHEMATICA f[n_]:=If[n==1, 0, Plus@@Last/@FactorInteger[n]]; Table[Sum[f[j], {j, i^2, (i+1)^2}], {i, 60}] (*Chandler*) CROSSREFS Cf. A001222. Sequence in context: A310561 A248349 A246301 * A003146 A063237 A026381 Adjacent sequences:  A160904 A160905 A160906 * A160908 A160909 A160910 KEYWORD easy,nonn AUTHOR Daniel Tisdale, May 29 2009 EXTENSIONS Edited and extended by Ray Chandler, May 06 2010 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 12 12:48 EST 2018. Contains 318063 sequences. (Running on oeis4.)