OFFSET
1,1
EXAMPLE
Number 28 (with sigma(28) = 56) is in sequence because sigma(26+sigma(26)) = sigma(84) = 224 = 4*56.
MAPLE
with(numtheory): A246911:=n->`if`(sigma(n+sigma(n)) = 4*sigma(n), n, NULL): seq(A246911(n), n=1..3*10^4); # Wesley Ivan Hurt, Sep 07 2014
PROG
(Magma) [n:n in[1..10000] | SumOfDivisors(n+SumOfDivisors(n)) eq 4*SumOfDivisors(n)]
(PARI)
for(n=1, 10^4, if(sigma(n+sigma(n))==4*sigma(n), print1(n, ", "))) \\ Derek Orr, Sep 07 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Sep 07 2014
STATUS
approved