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A094416 Array read by antidiagonals: generalized ordered Bell numbers Bo(r,n). 19

%I #40 Jan 12 2024 10:04:42

%S 1,2,3,3,10,13,4,21,74,75,5,36,219,730,541,6,55,484,3045,9002,4683,7,

%T 78,905,8676,52923,133210,47293,8,105,1518,19855,194404,1103781,

%U 2299754,545835,9,136,2359,39390,544505,5227236,26857659,45375130,7087261

%N Array read by antidiagonals: generalized ordered Bell numbers Bo(r,n).

%C Also, r times the number of (r+1)-level labeled linear rooted trees with n leaves.

%C "AIJ" (ordered, indistinct, labeled) transform of {r,r,r,...}.

%C Stirling transform of r^n*n!, i.e. of e.g.f. 1/(1-r*x).

%C Also, Bo(r,s) is ((x*d/dx)^n)(1/(1+r-r*x)) evaluated at x=1.

%C r-th ordered Bell polynomial (A019538) evaluated at n.

%C Bo(r,n) is the n-th moment of a geometric distribution with probability parameter = 1/(r+1). Here, geometric distribution is the number of failures prior to the first success. - _Geoffrey Critzer_, Jan 01 2019

%H G. C. Greubel, <a href="/A094416/b094416.txt">Antidiagonals n = 1..50, flattened</a>

%H Paul Barry, <a href="https://arxiv.org/abs/1803.06408">Three Études on a sequence transformation pipeline</a>, arXiv:1803.06408 [math.CO], 2018.

%H P. Blasiak, K. A. Penson and A. I. Solomon, <a href="https://arxiv.org/abs/quant-ph/0303030">Dobinski-type relations and the log-normal distribution</a>, arXiv:quant-ph/0303030, 2003.

%H C. G. Bower, <a href="/transforms2.html">Transforms</a>

%F E.g.f.: 1/(1 + r*(1 - exp(x))).

%F Bo(r, n) = Sum_{k=0..n} k!*r^k*Stirling2(n, k) = 1/(r+1) * Sum_{k>=1} k^n * (r/(r+1))^k, for r>0, n>0.

%F Recurrence: Bo(r, n) = r * Sum_{k=1..n} C(n, k)*Bo(r, n-k), with Bo(r, 0) = 1.

%F Bo(r,0) = 1, Bo(r,n) = r*Bo(r,n-1) - (r+1)*Sum_{j=1..n-1} (-1)^j * binomial(n-1,j) * Bo(r,n-j). - _Seiichi Manyama_, Nov 17 2023

%e Array begins as:

%e 1, 3, 13, 75, 541, 4683, 47293, ...

%e 2, 10, 74, 730, 9002, 133210, 2299754, ...

%e 3, 21, 219, 3045, 52923, 1103781, 26857659, ...

%e 4, 36, 484, 8676, 194404, 5227236, 163978084, ...

%e 5, 55, 905, 19855, 544505, 17919055, 687978905, ...

%e 6, 78, 1518, 39390, 1277646, 49729758, 2258233998, ...

%t Bo[_, 0]=1; Bo[r_, n_]:= Bo[r, n]= r*Sum[Binomial[n,k] Bo[r,n-k], {k, n}];

%t Table[Bo[r-n+1, n], {r, 10}, {n, r}] // Flatten (* _Jean-François Alcover_, Nov 03 2018 *)

%o (Magma)

%o A094416:= func< n,k | (&+[Factorial(j)*n^j*StirlingSecond(k,j): j in [0..k]]) >;

%o [A094416(n-k+1,k): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Jan 12 2024

%o (SageMath)

%o def A094416(n,k): return sum(factorial(j)*n^j*stirling_number2(k,j) for j in range(k+1)) # array

%o flatten([[A094416(n-k+1,k) for k in range(1,n+1)] for n in range(1,13)]) # _G. C. Greubel_, Jan 12 2024

%Y Rows 1-10 are A000670, A004123, A032033, A094417, A094418, A094419, A238464, A238465, A238466, A238467.

%Y Columns include A014105, A094421.

%Y Main diagonal is A094420.

%Y Antidiagonal sums are A094422.

%Y Cf. A019538, A131689, A344499.

%K nonn,tabl

%O 1,2

%A _Ralf Stephan_, May 02 2004

%E Offset corrected by _Geoffrey Critzer_, Jan 01 2019

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Last modified March 29 08:08 EDT 2024. Contains 371265 sequences. (Running on oeis4.)