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 A130078 Largest 2^x dividing A001623(n), the number of reduced three-line Latin rectangles. 2
 1, 4, 2, 8, 16, 64, 32, 64, 128, 512, 256, 2048, 8192, 16384, 4096, 65536, 32768, 131072, 65536, 262144, 524288, 2097152, 1048576, 2097152, 4194304, 16777216, 8388608, 134217728, 134217728, 1073741824, 134217728, 536870912, 2147483648 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 LINKS John Riordan, A recurrence relation for three-line Latin rectangles, Amer. Math. Monthly, 59 (1952), pp. 159-162. D. S. Stones, The many formulas for the number of Latin rectangles, Electron. J. Combin 17 (2010), A1. D. S. Stones and I. M. Wanless, Divisors of the number of Latin rectangles, J. Combin. Theory Ser. A 117 (2010), 204-215. FORMULA a(n) = A006519(A001623(n)). - Michel Marcus, Oct 02 2017 PROG (PARI) a001623(n) = n*(n-3)!*sum(i=0, n, sum(j=0, n-i, (-1)^j*binomial(3*i+j+2, j)<<(n-i-j)/(n-i-j)!)*i!); a(n) = 2^valuation(a001623(n), 2); \\ Michel Marcus, Oct 02 2017 CROSSREFS Cf. A001623, A006519, A130077, A130079. Sequence in context: A231777 A288181 A110622 * A230900 A204449 A172393 Adjacent sequences:  A130075 A130076 A130077 * A130079 A130080 A130081 KEYWORD nonn AUTHOR Douglas Stones (dssto1(AT)student.monash.edu.au), May 06 2007 STATUS approved

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Last modified February 25 21:00 EST 2020. Contains 332258 sequences. (Running on oeis4.)