A246854 Numbers n such that sigma(n+4) - sigma(n) = n + 4.

1, 4, 26, 122, 146, 458, 746, 3746, 47612, 16065500, 388978292, 5313509288, 64278616556

Offset: 1

Author

Jaroslav Krizek, Sep 05 2014

Keywords

• nonn
• more

Comments

Also numbers n such that A001065(n+4) = A000203(n). - Michel Marcus, Sep 06 2014

a(14) (if it exists) > 10^11. - Hiroaki Yamanouchi, Sep 10 2014

a(14) (if it exists) > 10^13. - Giovanni Resta, Jul 13 2015

Examples

			Number 26 is in sequence because sigma(26+4) - sigma(26) = 72 - 42 = 30 = 26 + 4.
		

Crossrefs

Cf. A000203, A067816, A246851, A246852, A246853, A246855.

Programs

Magma

[n:n in[1..10^7] | SumOfDivisors(n+4)-SumOfDivisors(n) eq n+4]

PARI

for(n=1,10^7,if(sigma(n+4)-sigma(n)==n+4,print1(n,", "))) \\ Derek Orr, Sep 05 2014

Extensions

a(10)-a(13) from Hiroaki Yamanouchi, Sep 10 2014