A005463 Number of simplices in barycentric subdivision of n-simplex.
1, 63, 1932, 46620, 1020600, 21538440, 451725120, 9574044480, 207048441600, 4595022432000, 105006251750400, 2475732702643200, 60284572969420800, 1516762345722624000, 39433286715863040000, 1059143615076298752000, 29378569022287220736000, 841159994641469927424000
Offset: 4
Keywords
References
- R. Austin, R. K. Guy, and R. Nowakowski, unpublished notes, circa 1987.
- R. K. Guy, personal communication.
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Links
- G. C. Greubel, Table of n, a(n) for n = 4..440
- R. Austin, R. K. Guy, and R. Nowakowski, Unpublished notes, 1987
- Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
- Rajesh Kumar Mohapatra and Tzung-Pei Hong, On the Number of Finite Fuzzy Subsets with Analysis of Integer Sequences, Mathematics (2022) Vol. 10, No. 7, 1161.
Programs
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Magma
[Factorial(n-4)*StirlingSecond(n+2,n-3): n in [4..35]]; // G. C. Greubel, Nov 22 2022
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Maple
a:= n-> Stirling2(2+n,n-3)*(n-4)!: seq(a(n), n=4..21); # Alois P. Heinz, Apr 27 2022
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Mathematica
Table[(n-4)!*StirlingS2[n+2, n-3], {n,4,35}] (* G. C. Greubel, Nov 22 2022 *)
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SageMath
[factorial(n-4)*stirling_number2(n+2,n-3) for n in range(4,36)] # G. C. Greubel, Nov 22 2022
Formula
Essentially Stirling numbers of second kind - see A028246.
a(n) = (n-4)! * Stirling2(n+2, n-3). - Alois P. Heinz, Apr 27 2022
Extensions
More terms from Alois P. Heinz, Apr 27 2022