This site is supported by donations to The OEIS Foundation.

 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 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.

Last modified August 18 13:53 EDT 2019. Contains 326100 sequences. (Running on oeis4.)