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A358399 a(n) is the number of reducible monic quartic polynomials (x^4 + r*x^3 + s*x^2 + t*x + u) with integer coefficients bounded by naïve height n (abs(r), abs(s), abs(t), abs(u) <= n).

%I A358399 #31 Jan 02 2023 09:01:55
%S A358399 47,271,810,1849,3395,5832,8915,13242,18465,25267,32874,43023,53662,
%T A358399 66957,81770,99374,117564,140303,163048,190757,219702,252465,285820,
%U A358399 326853,366732
%N A358399 a(n) is the number of reducible monic quartic polynomials (x^4 + r*x^3 + s*x^2 + t*x + u) with integer coefficients bounded by naïve height n (abs(r), abs(s), abs(t), abs(u) <= n).
%o A358399 (PARI){ a(n) = \\ A358399
%o A358399     my( ct = 0 );
%o A358399     for (c1 = -n, n,
%o A358399     for (c2 = -n, n,
%o A358399     for (c3 = -n, n,
%o A358399     for (c4 = -n, n,
%o A358399         if ( ! polisirreducible( Pol([1,c1,c2,c3,c4]) ), ct += 1 );
%o A358399     ); ); ); );
%o A358399     return( ct );
%o A358399 }
%o A358399 vector(12, n, a(n) )
%o A358399 \\ _Joerg Arndt_, Dec 05 2022
%Y A358399 Cf. A358398, A358400, A067274.
%K A358399 nonn,more
%O A358399 1,1
%A A358399 _Lorenz H. Menke, Jr._, Nov 13 2022