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 A254876 Triangular table T(n,k) = n! / Product_{m=(n-floor((2n)/(3^k))) .. (n-floor((n)/(3^k)))} m, read by rows T(1,1), T(2,1), T(2,2), T(3,1), T(3,2), T(3,3), ... 3
 1, 1, 1, 3, 2, 2, 4, 6, 6, 6, 5, 6, 24, 24, 24, 30, 24, 120, 120, 120, 120, 84, 120, 720, 720, 720, 720, 720, 112, 720, 5040, 5040, 5040, 5040, 5040, 5040, 1008, 6480, 40320, 40320, 40320, 40320, 40320, 40320, 40320, 4320, 50400, 362880, 362880, 362880, 362880, 362880, 362880, 362880, 362880 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS An auxiliary array for computing A088488. LINKS FORMULA T(n,k) = n! / Product_{m=(n-floor((2n)/(3^k))) .. (n-floor((n)/(3^k)))} m. EXAMPLE The first rows of the triangular table: 1 1, 1 3, 2, 2 4, 6, 6, 6 5, 6, 24, 24, 24 30, 24, 120, 120, 120, 120 84, 120, 720, 720, 720, 720, 720 112, 720, 5040, 5040, 5040, 5040, 5040, 5040 1008, 6480, 40320, 40320, 40320, 40320, 40320, 40320, 40320 4320, 50400, 362880, 362880, 362880, 362880, 362880, 362880, 362880, 362880 ... PROG (PARI) A254876bi(n, k) = n! / prod(i=(n-((2*n)\(3^k))), (n-(n\(3^k))), i); (Scheme) (define (A254876 n) (A254876bi (A002024 n) (A002260 n))) (define (A254876bi n k) (/ (A000142 n) (mul A000027 (- n (floor->exact (/ (* 2 n) (expt 3 k)))) (- n (floor->exact (/ n (expt 3 k))))))) (define (mul intfun lowlim uplim) (let multloop ((i lowlim) (res 1)) (cond ((> i uplim) res) (else (multloop (+ 1 i) (* res (intfun i))))))) CROSSREFS Cf. A002024, A002260, A088488, A254864. Sequence in context: A308194 A245572 A325596 * A249159 A230871 A111241 Adjacent sequences:  A254873 A254874 A254875 * A254877 A254878 A254879 KEYWORD nonn,tabl AUTHOR Antti Karttunen, Feb 09 2015 STATUS approved

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Last modified June 20 00:16 EDT 2021. Contains 345154 sequences. (Running on oeis4.)