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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A275358 The difference between A089580(n) and A089579(n). 3
0, 4, 10, 20, 41, 65, 114, 185, 297, 487, 809, 1339, 2253, 3824, 6544, 11297, 19620, 34216, 59926, 105258, 185356, 327039, 577906, 1022466, 1810789, 3209398, 5691825, 10099475, 17927609, 31833805, 56541947, 100449345, 178484340, 317187186, 563744378, 1002052726 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Submitted on the request of Omar E. Pol 17 July 2016. (A089579).

a(n) is the sum of A175066(m)-1 over such m that A117453(m)<10^n. - Andrey Zabolotskiy, Aug 17 2016

a(n+1)/a(n) goes to 1,778279...(A011007) when n goes to infinity. - Altug Alkan, Aug 22 2016

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..100

FORMULA

a(n) = A089580(n) - A089579(n).

EXAMPLE

a(2) = A089580(2)-A089579(2) = 4 because of the three terms: 16 = 2^4 = 4^2, 64 = 2^6 = 4^3 = 8^2 and 81 = 3^4 = 9^2; one for 16, two for 64 and one for 81 making a total of 4.

MATHEMATICA

f[n_] := Block[{lim = 10^n -1}, Sum[ (Floor[ lim^(1/k)] - 1)(1 + MoebiusMu[k]), {k, 2, Floor[ Log[2, lim]]}]]; Array[f, 36]

CROSSREFS

Cf. A011557, A089579, A089580.

Sequence in context: A038421 A049032 A100354 * A048008 A048019 A189586

Adjacent sequences:  A275355 A275356 A275357 * A275359 A275360 A275361

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Jul 24 2016

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 26 22:19 EDT 2021. Contains 348269 sequences. (Running on oeis4.)