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A246854 Numbers n such that sigma(n+4) - sigma(n) = n + 4. 4
1, 4, 26, 122, 146, 458, 746, 3746, 47612, 16065500, 388978292, 5313509288, 64278616556 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 21 10:48 EDT 2019. Contains 323443 sequences. (Running on oeis4.)