A227757 Numbers k such that antisigma(k) = antisigma(k+1) + 12; where antisigma(k) = A024816(k).

23, 29, 41, 53, 101, 113, 137, 173, 257, 281, 317, 353, 401, 617, 641, 653, 677, 761, 821, 941, 977, 1181, 1193, 1359, 1361, 1373, 1433, 1613, 1697, 1877, 1901, 2081, 2153, 2237, 2273, 2297, 2333, 2381, 2633, 2657, 2693, 2741, 2777, 2801, 3137, 3413, 3461, 3557

Offset: 1

Author

Jaroslav Krizek, Jul 26 2013

Keywords

• nonn

Comments

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

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

Examples

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

Links

• Jaroslav Krizek, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A024816, A227756.

Programs

Mathematica

Select[Range[3600],DivisorSigma[1,#+1]-DivisorSigma[1,#]==#+13 &] (* Stefano Spezia, Apr 18 2025 *)

PARI

is(n)=sigma(n+1)-sigma(n)==n+13 \\ Charles R Greathouse IV, Nov 25 2014