login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A231546 Numbers n such that sigma(n) = sigma(n-1). 3
15, 207, 958, 1335, 1365, 1635, 2686, 2975, 4365, 14842, 18874, 19359, 20146, 24958, 33999, 36567, 42819, 56565, 64666, 74919, 79827, 79834, 84135, 92686, 109215, 111507, 116938, 122074, 138238, 147455, 161002, 162603, 166935 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also, numbers n such that n = antisigma(n) - antisigma(n-1), where antisigma(n) = A024816(n) = the sum of the non-divisors of n that are between 1 and n.

LINKS

Table of n, a(n) for n=1..33.

FORMULA

a(n) = A002961(n) + 1.

EXAMPLE

15 = antisigma(15) - antisigma(14) = 96 - 81.

CROSSREFS

Cf. A002961, A024816 (antisigma(n)), A231545 (numbers n such that antisigma(n) = antisigma(n-1)).

Sequence in context: A075280 A093747 A061637 * A063906 A194481 A078265

Adjacent sequences:  A231543 A231544 A231545 * A231547 A231548 A231549

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Nov 11 2013

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 14 02:19 EDT 2019. Contains 327994 sequences. (Running on oeis4.)