A047920
Triangular array formed from successive differences of factorial numbers.
Original entry on oeis.org
1, 1, 0, 2, 1, 1, 6, 4, 3, 2, 24, 18, 14, 11, 9, 120, 96, 78, 64, 53, 44, 720, 600, 504, 426, 362, 309, 265, 5040, 4320, 3720, 3216, 2790, 2428, 2119, 1854, 40320, 35280, 30960, 27240, 24024, 21234, 18806, 16687, 14833, 362880, 322560
Offset: 0
Triangle begins:
1;
1, 0;
2, 1, 1;
6, 4, 3, 2;
24, 18, 14, 11, 9;
120, 96, 78, 64, 53, 44;
...
The left-hand column is the factorial numbers (A000142). The other numbers in the row are calculated by subtracting the numbers in the previous row. For example, row 4 is 6, 4, 3, 2, so row 5 is 4! = 24, 24 - 6 = 18, 18 - 4 = 14, 14 - 3 = 11, 11 - 2 = 9. - _Michael B. Porter_, Aug 05 2016
- Ch. A. Charalambides, Enumerative Combinatorics, Chapman & Hall/CRC, Boca Raton, Florida, 2002, p. 176, Table 5.3. [From Emeric Deutsch, Apr 21 2009]
- Reinhard Zumkeller, Rows n = 0..150 of triangle, flattened
- E. Deutsch and S. Elizalde, The largest and the smallest fixed points of permutations, arXiv:0904.2792 [math.CO], 2009.
- J. D. H. Dickson, Discussion of two double series arising from the number of terms in determinants of certain forms, Proc. London Math. Soc., 10 (1879), 120-122. [Annotated scanned copy]
- J. D. H. Dickson, Discussion of two double series arising from the number of terms in determinants of certain forms, Proc. London Math. Soc., 10 (1879), 120-122.
- Ira M. Gessel, Symmetric inclusion-exclusion, Séminaire Lotharingien de Combinatoire, B54b (2005).
- Peter Kagey, Ranking and Unranking Restricted Permutations, arXiv:2210.17021 [math.CO], 2022.
- Index entries for sequences related to factorial numbers
See
A068106 for another version of this triangle.
-
a047920 n k = a047920_tabl !! n !! k
a047920_row n = a047920_tabl !! n
a047920_tabl = map fst $ iterate e ([1], 1) where
e (row, n) = (scanl (-) (n * head row) row, n + 1)
-- Reinhard Zumkeller, Mar 05 2012
-
d[0] := 1: for n to 15 do d[n] := n*d[n-1]+(-1)^n end do: T := proc (n, k) if k <= n then sum(binomial(n-k, j)*d[n-j], j = 0 .. n-k) else 0 end if end proc: for n from 0 to 9 do seq(T(n, k), k = 0 .. n) end do; # yields sequence in triangular form - Emeric Deutsch, Jul 17 2009
# second Maple program:
T:= proc(n, k) option remember;
`if`(k=0, n!, T(n, k-1)-T(n-1, k-1))
end:
seq(seq(T(n, k), k=0..n), n=0..12); # Alois P. Heinz, Sep 01 2021
-
t[n_, k_] = Sum[(-1)^j*Binomial[k, j]*(n-j)!, {j, 0, n}]; Flatten[Table[t[n, k], {n, 0, 9}, {k, 0, n}]][[1 ;; 47]] (* Jean-François Alcover, May 17 2011, after Philippe Deléham *)
T[n_, k_] := n! Hypergeometric1F1[-k, -n, -1];
Table[T[n, k], {n, 0, 7}, {k, 0, n}] // Flatten (* Peter Luschny, Jul 28 2024 *)
-
row(n) = vector(n+1, k, k--; sum(j=0, n, (-1)^j * binomial(k, j)*(n-j)!)); \\ Michel Marcus, Sep 04 2021
A086764
Triangle T(n, k), read by row, related to Euler's difference table A068106 (divide column k of A068106 by k!).
Original entry on oeis.org
1, 0, 1, 1, 1, 1, 2, 3, 2, 1, 9, 11, 7, 3, 1, 44, 53, 32, 13, 4, 1, 265, 309, 181, 71, 21, 5, 1, 1854, 2119, 1214, 465, 134, 31, 6, 1, 14833, 16687, 9403, 3539, 1001, 227, 43, 7, 1, 133496, 148329, 82508, 30637, 8544, 1909, 356, 57, 8, 1
Offset: 0
Formatted as a square array:
1 3 7 13 21 31 43 57 ... A002061;
2 11 32 71 134 227 356 ... A094792;
9 53 181 465 1001 1909 ... A094793;
44 309 1214 3539 8544 ... A094794;
265 2119 9403 30637 ... A023043;
1854 16687 82508 ... A023044;
14833 148329 ... A023045;
Formatted as a triangular array (mirror of A076731):
1;
0 1;
1 1 1;
2 3 2 1;
9 11 7 3 1;
44 53 32 13 4 1;
265 309 181 71 21 5 1;
1854 2119 1214 465 134 31 6 1;
14833 16687 9403 3539 1001 227 43 7 1;
133496 148329 82508 30637 8544 1909 356 57 8 1;
Columns:
A000166,
A000155,
A000153,
A000261,
A001909,
A001910,
A176732,
A176733,
A176734,
A176735,
A176736.
-
A086764:= func< n,k | (&+[(-1)^j*Binomial(n-k,j)*Factorial(n-j): j in [0..n]])/Factorial(k) >;
[A086764(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Oct 05 2023
-
T[n_,k_]:=(1/k!)*Sum[(-1)^j*Binomial[n-k,j]*(n-j)!,{j,0,n}];Flatten[Table[T[n,k],{n,0,11},{k,0,n}]] (* Indranil Ghosh, Feb 20 2017 *)
T[n_, k_] := (n!/k!) HypergeometricPFQ[{k-n},{-n},-1];
Table[T[n,k], {n,0,9}, {k,0,n}] // Flatten (* Peter Luschny, Oct 05 2017 *)
-
def A086764(n,k): return sum((-1)^j*binomial(n-k,j)*factorial(n-j) for j in range(n+1))//factorial(k)
flatten([[A086764(n,k) for k in range(n+1)] for n in range(13)]) # G. C. Greubel, Oct 05 2023
A176734
a(n) = (n+7)*a(n-1) + (n-1)*a(n-2), a(-1)=0, a(0)=1.
Original entry on oeis.org
1, 8, 73, 746, 8425, 104084, 1395217, 20157542, 312129649, 5155334720, 90449857081, 1679650774658, 32908313146393, 678322072223756, 14672571587601985, 332293083938376254, 7862829504396683617, 194024597448534426872, 4984283037788104293289, 133083801736564331309210
Offset: 0
Necklaces and 8 cords problem. For n=4 one considers the following weak 2 part compositions of 4: (4,0), (3,1), (2,2), and (0,4), where (1,3) does not appear because there are no necklaces with 1 bead. These compositions contribute respectively !4*1,binomial(4,3)*!3*c8(1), (binomial(4,2)*!2)*c8(2), and 1*c8(4) with the subfactorials !n:=A000166(n) (see the necklace comment there) and the c8(n):=A049388(n) numbers for the pure 8-cord problem (see the remark on the e.g.f. for the k cords problem in A000153; here for k=8: 1/(1-x)^8). This adds up as 9 + 4*2*8 + (6*1)*72 + 7920 = 8425 = a(4).
Cf.
A176733 (necklaces and k=7 cords).
-
nxt[{n_,a_,b_}]:={n+1,b,(n+8)b+n*a}; Transpose[NestList[nxt,{1,1,8},20]][[2]] (* Harvey P. Dale, Mar 19 2013 *)
Table[(-1)^n HypergeometricPFQ[{9, -n}, {}, 1], {n, 0, 20}] (* Benedict W. J. Irwin, May 29 2016 *)
A247490
Square array read by antidiagonals: A(k, n) = (-1)^(n+1)* hypergeom([k, -n+1], [], 1) for n>0 and A(k,0) = 0 (n>=0, k>=1).
Original entry on oeis.org
0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 2, 3, 2, 0, 1, 3, 7, 11, 9, 0, 1, 4, 13, 32, 53, 44, 0, 1, 5, 21, 71, 181, 309, 265, 0, 1, 6, 31, 134, 465, 1214, 2119, 1854, 0, 1, 7, 43, 227, 1001, 3539, 9403, 16687, 14833, 0, 1, 8, 57, 356, 1909, 8544, 30637, 82508, 148329, 133496
Offset: 0
k\n
[1], 0, 1, 0, 1, 2, 9, 44, 265, 1854, ... A000166
[2], 0, 1, 1, 3, 11, 53, 309, 2119, 16687, ... A000255
[3], 0, 1, 2, 7, 32, 181, 1214, 9403, 82508, ... A000153
[4], 0, 1, 3, 13, 71, 465, 3539, 30637, 296967, ... A000261
[5], 0, 1, 4, 21, 134, 1001, 8544, 81901, 870274, ... A001909
[6], 0, 1, 5, 31, 227, 1909, 18089, 190435, 2203319, ... A001910
[7], 0, 1, 6, 43, 356, 3333, 34754, 398959, 4996032, ... A176732
[8], 0, 1, 7, 57, 527, 5441, 61959, 770713, 10391023, ... A176733
The referenced sequences may have a different offset or other small deviations.
-
A := (k,n) -> `if`(n<2,n,hypergeom([k,-n+1],[],1)*(-1)^(n+1));
seq(print(seq(round(evalf(A(k,n),100)), n=0..8)), k=1..8);
-
from mpmath import mp, hyp2f0
mp.dps = 25; mp.pretty = True
def A247490(k, n):
if n < 2: return n
if k == 1 and n == 2: return 0 # (failed to converge)
return int((-1)^(n+1)*hyp2f0(k, -n+1, 1))
for k in (1..8): print([k], [A247490(k, n) for n in (0..8)])
A284204
Eighth column of Euler's difference table in A068106.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 5040, 35280, 287280, 2656080, 27422640, 312273360, 3884393520, 52370755920, 760381337520, 11824686110160, 196038409800240, 3450899827705680, 64272619406504880, 1262590566656060880, 26087355385405781040, 565510731026706254160
Offset: 1
a(11)=27422640 since this is the number of permutations in S11 that avoid substrings {18,29,3(10),4(11)}.
-
With[{k = 8}, ConstantArray[0, k - 2]~Join~Table[Sum[(-1)^j*Binomial[n - (k - 1), j] (n - j)!, {j, 0, n - (k - 1)}], {n, k - 1, k + 12}]] (* Michael De Vlieger, Mar 26 2017 *)
A336246
Array read by upwards antidiagonals: T(n,k) is the number of ways to place n persons on different seats such that each person number p, 1 <= p <= n, differs from the seat number s(p), 1 <= s(p) <= n+k, k >= 0.
Original entry on oeis.org
0, 1, 1, 2, 3, 2, 9, 11, 7, 3, 44, 53, 32, 13, 4, 265, 309, 181, 71, 21, 5, 1854, 2119, 1214, 465, 134, 31, 6, 14833, 16687, 9403, 3539, 1001, 227, 43, 7, 133496, 148329, 82508, 30637, 8544, 1909, 356, 57, 8, 1334961, 1468457, 808393, 296967, 81901, 18089, 3333, 527, 73, 9
Offset: 1
For k=1, the n-tuples of seat numbers are:
- for n=1: 2 => T(1,1) = 1.
- for n=2: 21, 23, 31 => T(2,1) = 3,
21: person 1 sits on seat 2 and vice versa.
A counterexample is 13 because person 1 would sit on seat 1.
- for n=3: 214,231,234,241,312,314,341,342,412,431,432 => T(3,1) = 11.
Array begins:
0 1 2 3 4 ...
1 3 7 13 21 ...
2 11 32 71 134 ...
9 53 181 465 1001 ...
44 309 1214 3539 8544 ...
.. ... .... .... ....
Cf.
A000166,
A000255,
A000153,
A000261,
A001909,
A001910,
A176732,
A176733,
A176734,
A176735,
A176736.
-
block(nr: 0, k: -1, mmax: 55,
/*First mmax terms are returned, recurrence used*/
a: makelist(0, n, 1, mmax),
while nr
-
block(n: 1, k: 0, mmax: 55,
/*First mmax terms are returned, explicit formula used*/
a: makelist(0, n, 1, mmax),
for m from 1 thru mmax do (su: 0,
for r from 0 thru n do su: su+(-1)^r*binomial(n,r)*(n+k-r)!/k!,
a[m]: su, if n=1 then (n: k+2, k: 0) else (n: n-1, k: k+1)),
return(a));
Showing 1-6 of 6 results.
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