A246855 Numbers k such that sigma(k+5) - sigma(k) = k + 5.

3577, 14773, 2843579

Offset: 1

Author

Jaroslav Krizek, Sep 05 2014

Keywords

• nonn
• bref
• more

Comments

Also numbers k such that A001065(k+5) = A000203(k). - Michel Marcus, Sep 06 2014

a(4) (if it exists) > 10^11. - Hiroaki Yamanouchi, Sep 10 2014

a(4) (if it exists) > 10^13. - Giovanni Resta, Jul 13 2015

No other terms < 2.7*10^15. - Jud McCranie, Jul 27 2025

Examples

			Number 3577 is in sequence because sigma(3577+5) - sigma(3577) = 7800 - 4218 = 3582 = 3577 + 5.
		

Crossrefs

Cf. A000203, A067816, A246851, A246852, A246853, A246854.

Programs

Magma

[n:n in[1..10^7] | SumOfDivisors(n+5)-SumOfDivisors(n) eq n+5];

Mathematica

Select[Range[285*10^4],DivisorSigma[1,#+5]-DivisorSigma[1,#]==#+5&] (* Harvey P. Dale, Jun 21 2024 *)

PARI

for(n=1,10^7,if(sigma(n+5)-sigma(n)==n+5,print1(n,", "))) \\ Derek Orr, Sep 05 2014