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

1,2

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

Links

Table of n, a(n) for n=1..13.

Example

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

Prog

(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

Crossrefs

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

Sequence in context: A267675 A140804 A147621 * A267847 A211166 A245460

Adjacent sequences: A246851 A246852 A246853 * A246855 A246856 A246857

Keyword

nonn,more

Author

Jaroslav Krizek, Sep 05 2014

Extensions

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

Status

approved