OFFSET
1,1
LINKS
Hieronymus Fischer, Table of n, a(n) for n = 1..10000
EXAMPLE
a(2)=48 since 48=2*2*2*2*3 and sqrt(4*2^2+3^2)=sqrt(25)=5.
MATHEMATICA
srssQ[n_]:=IntegerQ[Sqrt[Total[Flatten[Table[#[[1]], #[[2]]]&/@ FactorInteger[ n]]^2]]]; Select[Range[10000], CompositeQ[#]&&srssQ[#]&] (* Harvey P. Dale, Jan 22 2019 *)
PROG
(PARI) is(n)=my(f=factor(n)); issquare(sum(i=1, #f~, f[i, 1]^2*f[i, 2])) && !isprime(n) && n>1 \\ Charles R Greathouse IV, Apr 29 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Hieronymus Fischer, Nov 11 2007
STATUS
approved