A246853 Numbers n such that sigma(n+3) - sigma(n) = n + 3.

7, 6285, 4693485, 54028959, 75898473, 724416741, 2359059709, 4901493769, 321212249593, 511578306649, 534245763769, 6158645822473

Offset: 1

Author

Jaroslav Krizek, Sep 05 2014

Keywords

• nonn
• more

Comments

Also numbers n such that A001065(n+3) = A000203(n). - Michel Marcus, Sep 06 2014

a(13) > 10^13. - Giovanni Resta, Jul 13 2015

Examples

			Number 7 is in sequence because sigma(7+3) - sigma(7) = 18 - 8 = 10 = 7 + 3.
		

Crossrefs

Cf. A000203, A067816, A246851, A246852, A246854, A246855.

Programs

Magma

[n:n in[1..10^7] | SumOfDivisors(n+3)-SumOfDivisors(n) eq n+3]

PARI

for(n=1,10^7,if(sigma(n+3)-sigma(n)==n+3,print1(n,", "))) \\ Derek Orr, Sep 05 2014

Extensions

a(4)-a(8) from Hiroaki Yamanouchi, Sep 10 2014

a(9)-a(12) from Giovanni Resta, Jul 13 2015