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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). 2
 47, 271, 810, 1849, 3395, 5832, 8915, 13242, 18465, 25267, 32874, 43023, 53662, 66957, 81770, 99374, 117564, 140303, 163048, 190757, 219702, 252465, 285820, 326853, 366732 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS PROG (PARI){ a(n) = \\ A358399 my( ct = 0 ); for (c1 = -n, n, for (c2 = -n, n, for (c3 = -n, n, for (c4 = -n, n, if ( ! polisirreducible( Pol([1, c1, c2, c3, c4]) ), ct += 1 ); ); ); ); ); return( ct ); } vector(12, n, a(n) ) \\ Joerg Arndt, Dec 05 2022 CROSSREFS Cf. A358398, A358400, A067274. Sequence in context: A078965 A186169 A142119 * A231440 A142164 A201545 Adjacent sequences: A358396 A358397 A358398 * A358400 A358401 A358402 KEYWORD nonn,more AUTHOR Lorenz H. Menke, Jr., Nov 13 2022 STATUS approved

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Last modified March 24 15:37 EDT 2023. Contains 361479 sequences. (Running on oeis4.)