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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A227757 Numbers n such that antisigma(n) = antisigma(n+1) + 12; where antisigma(n) = A024816(n). 2

%I #10 Nov 25 2014 16:33:20

%S 23,29,41,53,101,113,137,173,257,281,317,353,401,617,641,653,677,761,

%T 821,941,977,1181,1193,1359,1361,1373,1433,1613,1697,1877,1901,2081,

%U 2153,2237,2273,2297,2333,2381,2633,2657,2693,2741,2777,2801,3137,3413,3461,3557

%N Numbers n such that antisigma(n) = antisigma(n+1) + 12; where antisigma(n) = A024816(n).

%C Supersequence of A227756 (primes p such that sigma(p+1) = 2*p+14).

%C The composites in this sequence are rare: 1359, 453967, ... (no more up to 10^6).

%H Jaroslav Krizek, <a href="/A227757/b227757.txt">Table of n, a(n) for n = 1..500</a>

%e 1359 is in sequence because antisigma(1359) = 922144 = antisigma(1360) + 12 = 922132 + 12.

%o (PARI) is(n)=sigma(n+1)-sigma(n)==n+13 \\ _Charles R Greathouse IV_, Nov 25 2014

%Y Cf. A024816, A227756.

%K nonn

%O 1,1

%A _Jaroslav Krizek_, Jul 26 2013

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 April 23 13:41 EDT 2024. Contains 371914 sequences. (Running on oeis4.)