login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

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!)
A259935 Infinite sequence of positive integers such that a(n) = A000005(a(1) + a(2) + ... + a(n)) for all n >= 1. 9
2, 4, 6, 6, 4, 8, 4, 8, 4, 8, 4, 4, 8, 8, 12, 4, 8, 4, 8, 4, 3, 4, 4, 15, 8, 10, 4, 8, 8, 8, 4, 16, 4, 8, 8, 6, 6, 8, 4, 16, 4, 8, 12, 4, 4, 8, 4, 16, 12, 4, 8, 4, 8, 8, 16, 4, 8, 8, 8, 8, 8, 8, 4, 16, 4, 8, 12, 8, 16, 12, 8, 16, 12, 4, 4, 8, 8, 8, 8, 8, 24, 8, 12, 8, 4, 8, 8, 8, 16, 8, 6, 6, 8, 4, 8, 4, 8, 8, 12, 8, 18, 8, 32, 24, 18, 4, 8, 16, 4, 16, 4, 8, 12, 8, 8, 8, 8, 8, 8, 12 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Falcao (2015) proved that such an infinite sequence exists. Numerical evidence suggests that it may also be unique (cf. A259934).

If there are infinitely many n with a(n) = a(n+1), then A175304 is infinite (see comment in A259934). - Vladimir Shevelev, Jul 21 2015

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 1..64800 (Based on Robert Israel's b-file for A259934.)

Falcao et al., Sequence and divisors, 2015. (in Russian)

FORMULA

a(n) = A000005(A259934(n)) = A259934(n) - A259934(n-1).

gcd(a(n), A259934(n)) = A286540(n) = A009191(A259934(n)). - Antti Karttunen, Nov 26 2017

CROSSREFS

First differences of A259934.

Cf. A000005, A260257, A260085, A260123, A286540.

Sequence in context: A248844 A257821 A238365 * A054584 A049041 A092337

Adjacent sequences: A259932 A259933 A259934 * A259936 A259937 A259938

KEYWORD

nonn,nice

AUTHOR

Max Alekseyev, Jul 09 2015

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 7 03:44 EST 2022. Contains 358649 sequences. (Running on oeis4.)