OFFSET
1,1
COMMENTS
The asymptotic density of this sequence is A336065 - A059956 = 0.24103009315... . - Amiram Eldar, Jan 05 2024
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
MAPLE
A051903 := proc(n) local a, ifs, p, e; a := 1 ; max( seq(op(2, p), p=ifactors(n)[2]) ); end: isA013929 := proc(n) RETURN( not isprime(n) and A051903(n) > 1 ) ; end: isA144976 := proc(n) RETURN( isA013929(n) and (n mod A051903(n)) = 0 ); end: for n from 4 to 400 do if isA144976(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Oct 24 2008
MATHEMATICA
Select[Range[300], !SquareFreeQ[#]&&Divisible[#, Max[FactorInteger[#][[All, 2]]]]&] (* Harvey P. Dale, Jul 01 2017 *)
PROG
(PARI) is(n) = {my(e = factor(n)[, 2], emax); if(n == 1, 0, emax = vecmax(e); emax > 1 && !(n % emax)); } \\ Amiram Eldar, Jan 05 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Sep 28 2008
EXTENSIONS
Adapted definition, inserted 18, 20 and extended. - R. J. Mathar, Oct 24 2008
STATUS
approved