This site is supported by donations to The OEIS Foundation.

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A146323 a(n)= integer part [ Sum_i=1..n (1/phi(i))] 0
 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Looking on the number of 1`s, 2`s,...k`s in this sequence we obtain the sequence (1,2,4,5,9,16,25,42,72,...). Lim_k-->oo [number of (k+1)`s / number of(k`s)] = sqrt(e). LINKS MATHEMATICA IntegerPart[Accumulate[1/EulerPhi[Range[110]]]] (* Harvey P. Dale, Dec 19 2015 *) CROSSREFS Cf. A000010 Sequence in context: A156079 A268708 A061555 * A071626 A182008 A106457 Adjacent sequences:  A146320 A146321 A146322 * A146324 A146325 A146326 KEYWORD nonn AUTHOR Ctibor O. Zizka, Oct 30 2008 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.