OFFSET
1,1
EXAMPLE
Number 15456 (with sigma(15456) = 48384) is in sequence because sigma(15456+sigma(15456)) = sigma(63840) = 241920 = 5*48384.
MAPLE
with(numtheory): A246912:=n->`if`(sigma(n+sigma(n)) = 5*sigma(n), n, NULL): seq(A246912(n), n=1..10^6); # Wesley Ivan Hurt, Sep 07 2014
MATHEMATICA
Select[Range[16*10^5], DivisorSigma[1, #+DivisorSigma[1, #]] == 5*DivisorSigma[ 1, #]&] (* Harvey P. Dale, Mar 13 2016 *)
PROG
(Magma) [n:n in[1..10^7] | SumOfDivisors(n+SumOfDivisors(n))eq 5*SumOfDivisors(n)]
(PARI)
for(n=1, 10^7, if(sigma(n+sigma(n))==5*sigma(n), print1(n, ", "))) \\ Derek Orr, Sep 07 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Sep 07 2014
STATUS
approved