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!)
A175265 a(1)=1. a(n) = the smallest integer > a(n-1) where |d(a(n)) - d(a(n-1))| = 1; d(n) is the number of divisors of n. 2
1, 2, 4, 5, 9, 10, 16, 18, 64, 66, 100, 102, 196, 208, 225, 230, 256, 258, 441, 442, 484, 488, 676, 678, 729, 730, 1089, 1090, 1156, 1158, 1225, 1235, 1444, 1446, 1521, 1526, 2116, 2118, 2601, 2607, 3025, 3026, 3249, 3262, 3364, 3367, 3844, 3846, 4225, 4233 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

nxt[n_]:=Module[{k=n+1}, While[Abs[DivisorSigma[0, n]-DivisorSigma[0, k]] != 1, k++]; k]; NestList[nxt, 1, 50] (* Harvey P. Dale, Oct 10 2012 *)

CROSSREFS

A175266

Sequence in context: A039891 A280729 A213011 * A320225 A070924 A351993

Adjacent sequences: A175262 A175263 A175264 * A175266 A175267 A175268

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 18 2010

EXTENSIONS

More terms from Jon E. Schoenfield, Jun 13 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 28 22:51 EST 2022. Contains 358421 sequences. (Running on oeis4.)