A246049
Number T(n,k) of endofunctions on [n] where the smallest cycle length equals k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
1, 0, 1, 0, 3, 1, 0, 19, 6, 2, 0, 175, 51, 24, 6, 0, 2101, 580, 300, 120, 24, 0, 31031, 8265, 4360, 2160, 720, 120, 0, 543607, 141246, 74130, 41160, 17640, 5040, 720, 0, 11012415, 2810437, 1456224, 861420, 430080, 161280, 40320, 5040
Offset: 0
Triangle T(n,k) begins:
1;
0, 1;
0, 3, 1;
0, 19, 6, 2;
0, 175, 51, 24, 6;
0, 2101, 580, 300, 120, 24;
0, 31031, 8265, 4360, 2160, 720, 120;
0, 543607, 141246, 74130, 41160, 17640, 5040, 720;
...
Columns k=0-10 give:
A000007,
A045531,
A246189,
A246190,
A246191,
A246192,
A246193,
A246194,
A246195,
A246196,
A246197.
Main diagonal gives
A000142(n-1) for n>0.
-
with(combinat):
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i>n, 0,
add((i-1)!^j*multinomial(n, n-i*j, i$j)/j!*
b(n-i*j, i+1), j=0..n/i)))
end:
A:= (n, k)-> add(binomial(n-1, j-1)*n^(n-j)*b(j, k), j=0..n):
T:= (n, k)-> `if`(k=0, `if`(n=0, 1, 0), A(n, k) -A(n, k+1)):
seq(seq(T(n, k), k=0..n), n=0..12);
-
multinomial[n_, k_List] := n!/Times @@ (k!);
b[n_, i_] := b[n, i] = If[n == 0, 1, If[i>n, 0,
Sum[(i-1)!^j*multinomial[n, {n-i*j, Sequence @@ Table[i, {j}]}]/j!*
b[n-i*j, i+1], {j, 0, n/i}]]];
A[n_, k_] := Sum[Binomial[n-1, j-1]*n^(n-j)*b[j, k], {j, 0, n}];
T[n_, k_] := If[k == 0, If[n == 0, 1, 0], A[n, k] - A[n, k+1]];
Table[Table[T[n, k], {k, 0, n}], {n, 0, 12}] // Flatten (* Jean-François Alcover, Jan 06 2015, after Alois P. Heinz *)
A055858
Coefficient triangle for certain polynomials.
Original entry on oeis.org
1, 1, 2, 4, 9, 6, 27, 64, 48, 36, 256, 625, 500, 400, 320, 3125, 7776, 6480, 5400, 4500, 3750, 46656, 117649, 100842, 86436, 74088, 63504, 54432, 823543, 2097152, 1835008, 1605632, 1404928, 1229312, 1075648, 941192, 16777216, 43046721
Offset: 0
{1}; {1,2}; {4,9,6}; {27,64,48,36}; ...
Fourth row polynomial (n=3): p(3,x) = 27 + 64*x + 48*x^2 + 36*x^3.
-
a[n_, m_] /; n < m = 0; a[0, 0] = 1; a[n_, 0] := n^n; a[n_, m_] := n^(m-1)*(n+1)^(n-m+1); Table[a[n, m], {n, 0, 8}, {m, 0, n}] // Flatten (* Jean-François Alcover, Jun 20 2013 *)
A055869
a(n) = (n+1)^n - n^n.
Original entry on oeis.org
1, 5, 37, 369, 4651, 70993, 1273609, 26269505, 612579511, 15937424601, 457696700077, 14381984674225, 490839666661891, 18080919199832609, 715027614225987601, 30214447801957316865, 1358671297852359767791, 64780942222614703957417, 3264460344339686410876021
Offset: 1
A354794
Triangle read by rows. The Bell transform of the sequence {m^m | m >= 0}.
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 4, 3, 1, 0, 27, 19, 6, 1, 0, 256, 175, 55, 10, 1, 0, 3125, 2101, 660, 125, 15, 1, 0, 46656, 31031, 9751, 1890, 245, 21, 1, 0, 823543, 543607, 170898, 33621, 4550, 434, 28, 1, 0, 16777216, 11012415, 3463615, 688506, 95781, 9702, 714, 36, 1
Offset: 0
Triangle T(n, k) begins:
[0] 1;
[1] 0, 1;
[2] 0, 1, 1;
[3] 0, 4, 3, 1;
[4] 0, 27, 19, 6, 1;
[5] 0, 256, 175, 55, 10, 1;
[6] 0, 3125, 2101, 660, 125, 15, 1;
[7] 0, 46656, 31031, 9751, 1890, 245, 21, 1;
[8] 0, 823543, 543607, 170898, 33621, 4550, 434, 28, 1;
[9] 0, 16777216, 11012415, 3463615, 688506, 95781, 9702, 714, 36, 1;
- Louis Comtet, Advanced Combinatorics. Reidel, Dordrecht, 1974, p. 139-140.
Cf.
A264428,
A039621 (signed variant),
A195979 (row sums),
A000312 (column 1),
A045531 (column 2),
A281596 (column 3),
A281595 (column 4),
A000217 (diagonal 1),
A215862 (diagonal 2),
A354795 (matrix inverse),
A137452 (Abel).
-
T := (n, k) -> if n = k then 1 else
add((-1)^j*(n-j-1)^(n-1)/(j!*(k-1-j)!), j = 0.. k-1) fi:
seq(seq(T(n, k), k = 0..n), n = 0..9);
# Alternatively, using the function BellMatrix from A264428:
BellMatrix(n -> n^n, 9);
# Or by recursion:
R := proc(n, k, m) option remember;
if k < 0 or n < 0 then 0 elif k = 0 then 1 else
m*R(n, k-1, m) + R(n-1, k, m+1) fi end:
A039621 := (n, k) -> ifelse(n = 0, 1, R(k-1, n-k, n-k)):
-
Unprotect[Power]; Power[0, 0] = 1; pow[n_] := n^n;
R = Range[0, 9]; T[n_, k_] := BellY[n, k, pow[R]];
Table[T[n, k], {n, R}, {k, 0, n}] // Flatten
-
from functools import cache
@cache
def t(n, k, m):
if k < 0 or n < 0: return 0
if k == 0: return n ** k
return m * t(n, k - 1, m) + t(n - 1, k, m + 1)
def A354794(n, k): return t(k - 1, n - k, n - k) if n != k else 1
for n in range(9): print([A354794(n, k) for k in range(n + 1)])
A066274
Number of endofunctions of [n] such that 1 is not a fixed point.
Original entry on oeis.org
0, 2, 18, 192, 2500, 38880, 705894, 14680064, 344373768, 9000000000, 259374246010, 8173092077568, 279577021469772, 10318292052303872, 408700964355468750, 17293822569102704640, 778579070010669895696, 37160496515557841043456, 1874292305362402347591138
Offset: 1
a(2)=2: [1->2,2->1], [1->2,2->2].
A199656
Triangular array read by rows, T(n,k) is the number of functions from {1,2,...,n} into {1,2,...,n} with maximum value of k.
Original entry on oeis.org
1, 1, 3, 1, 7, 19, 1, 15, 65, 175, 1, 31, 211, 781, 2101, 1, 63, 665, 3367, 11529, 31031, 1, 127, 2059, 14197, 61741, 201811, 543607, 1, 255, 6305, 58975, 325089, 1288991, 4085185, 11012415, 1, 511, 19171, 242461, 1690981, 8124571, 30275911, 93864121, 253202761
Offset: 1
Triangle begins:
1
1 3
1 7 19
1 15 65 175
1 31 211 781 2101
1 63 665 3367 11529 31031
1 127 2059 14197 61741 201811 543607
...
-
/* As triangle: */ [[k^n - (k-1)^n: k in [1..n]]: n in [1..9]]; // Vincenzo Librandi, Jan 28 2013
-
Table[Table[(1-((i-1)/i)^n) i^n,{i,1,n}],{n,1,8}]//Grid
Flatten[Table[k^n - (k-1)^n, {n, 0, 10}, {k, 1, n}]] (* Vincenzo Librandi, Jan 28 2013 *)
A039621
Triangle of Lehmer-Comtet numbers of 2nd kind.
Original entry on oeis.org
1, -1, 1, 4, -3, 1, -27, 19, -6, 1, 256, -175, 55, -10, 1, -3125, 2101, -660, 125, -15, 1, 46656, -31031, 9751, -1890, 245, -21, 1, -823543, 543607, -170898, 33621, -4550, 434, -28, 1, 16777216, -11012415, 3463615, -688506, 95781, -9702, 714, -36, 1
Offset: 1
The triangle T(n, k) begins:
[1] 1;
[2] -1, 1;
[3] 4, -3, 1;
[4] -27, 19, -6, 1;
[5] 256, -175, 55, -10, 1;
[6] -3125, 2101, -660, 125, -15, 1;
[7] 46656, -31031, 9751, -1890, 245, -21, 1;
[8] -823543, 543607, -170898, 33621, -4550, 434, -28, 1;
-
R := proc(n, k, m) option remember;
if k < 0 or n < 0 then 0 elif k = 0 then 1 else
m*R(n, k-1, m) + R(n-1, k, m+1) fi end:
A039621 := (n, k) -> (-1)^(n-k)*R(k-1, n-k, n-k):
seq(seq(A039621(n, k), k = 1..n), n = 1..9); # Peter Luschny, Jun 10 2022 after Vladimir Kruchinin
-
a[1, 1] = 1; a[n_, k_] := 1/(k-1)! Sum[((-1)^(n-k-i)*Binomial[k-1, i]*(n-i-1)^(n-1)), {i, 0, k-1}];
Table[a[n, k], {n, 1, 10}, {k, 1, n}]//Flatten (* Jean-François Alcover, Jun 03 2019 *)
-
T(n,k,m):=if k<0 or n<0 then 0 else if k=0 then 1 else m*T(n,k-1,m)+T(n-1,k,m+1);
a(n,k):=if nVladimir Kruchinin, Mar 07 2020
-
tabl(nn) = {for (n = 1, nn, for (k = 1, n, print1(sum(i = 0, k-1,(-1)^(n-k-i)*binomial(k-1, i)*(n-i-1)^(n-1))/(k-1)!, ", ");); print(););} \\ Michel Marcus, Aug 28 2013
-
# uses[bell_matrix from A264428]
# Adds 1,0,0,0,... as column 0 at the left side of the triangle.
bell_matrix(lambda n: (-n)^n, 7) # Peter Luschny, Jan 16 2016
A281596
a(n) = ((n-2)^n - 2*(n-1)^n + n^n)/2.
Original entry on oeis.org
0, 0, 1, 6, 55, 660, 9751, 170898, 3463615, 79669320, 2050086511, 58346365110, 1819621847407, 61705703989020, 2260586259354151, 88971796139662842, 3743940350046570751, 167735288431662235920, 7971302827015366403551, 400510700317394780627934, 21212944650652080893863087
Offset: 0
-
a := n -> ((n-2)^n-2*(n-1)^n+n^n)/2:
seq(a(n), n=0..21);
-
A281596[n_] := If[n == 0, 0, ((n-2)^n - 2*(n-1)^n + n^n)/2];
Array[A281596, 25, 0] (* Paolo Xausa, Jul 10 2024 *)
A060226
a(n) = n^n - n*(n-1)^(n-1).
Original entry on oeis.org
1, 0, 2, 15, 148, 1845, 27906, 496951, 10188872, 236425545, 6125795110, 175311670611, 5492360400924, 186965800764925, 6871755333266474, 271213787997489135, 11440441827615801616, 513645612633274386705
Offset: 0
-
a060226 0 = 1
a060226 n = a000312 n - n * a000312 (n - 1)
-- Reinhard Zumkeller, Aug 27 2012
-
A060226:= func< n | n^n - n*(n-1)^(n-1) >;
[A060226(n): n in [0..30]]; // G. C. Greubel, Nov 03 2024
-
f := n-> n*sum(binomial(n-1,j-1)*(n-1)^(n-j), j=2..n);
g := n-> n^n -n*(n-1)^(n-1);
h := n-> sum(binomial(n,j)*j^(j-1)*(n-j)^(n-j), j=2..n);
k := n-> sum(binomial(n,j-1)*(j-1)^(j-1)*(n-j)^(n-j), j=2..n); # then a(n)=f(n)=g(n)=h(n)=k(n)
-
Join[{1,0},Table[n^n-n*(n-1)^(n-1),{n,2,20}]] (* Harvey P. Dale, Nov 16 2012 *)
-
{ for (n=0, 100, write("b060226.txt", n, " ", n^n - n*(n - 1)^(n - 1)); ) } \\ Harry J. Smith, Jul 03 2009
-
def A060226(n): return n^n - n*(n-1)^(n-1)
[A060226(n) for n in range(31)] # G. C. Greubel, Nov 03 2024
A350134
Number of endofunctions on [n] with at least one isolated fixed point.
Original entry on oeis.org
0, 1, 1, 10, 87, 1046, 15395, 269060, 5440463, 124902874, 3208994379, 91208536112, 2841279322871, 96258245162678, 3523457725743059, 138573785311560916, 5827414570508386335, 260928229315498155314, 12393729720071855683739, 622422708333615857463608
Offset: 0
a(3) = 10: 123, 122, 133, 132, 121, 323, 321, 113, 223, 213.
-
g:= proc(n) option remember; add(n^(n-j)*(n-1)!/(n-j)!, j=1..n) end:
b:= proc(n, t) option remember; `if`(n=0, t, add(g(i)*
b(n-i, `if`(i=1, 1, t))*binomial(n-1, i-1), i=1..n))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..23);
-
g[n_] := g[n] = Sum[n^(n - j)*(n - 1)!/(n - j)!, {j, 1, n}];
b[n_, t_] := b[n, t] = If[n == 0, t, Sum[g[i]*
b[n - i, If[i == 1, 1, t]]*Binomial[n - 1, i - 1], {i, 1, n}]];
a[n_] := b[n, 0];
Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Apr 27 2022, after Alois P. Heinz *)
Showing 1-10 of 23 results.
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