A165680
Triangle of the divisors of the coefficients of triangles A138771 and A165675.
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 6, 1, 1, 1, 2, 6, 24, 1, 1, 1, 2, 6, 24, 120, 1, 1, 1, 2, 6, 24, 120, 720, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880
Offset: 1
Triangle starts:
1,
1, 1,
1, 1, 1,
1, 1, 1, 2,
1, 1, 1, 2, 6,
1, 1, 1, 2, 6, 24,
1, 1, 1, 2, 6, 24, 120,
1, 1, 1, 2, 6, 24, 120, 720,
1, 1, 1, 2, 6, 24, 120, 720, 5040,
1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320,
1, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880,
...
A159333 equals, for n=>-1, all right hand columns.
-
nmax:=11: for n from 1 to nmax do a(n,1):=1 od: for n from 2 to nmax do for m from 2 to n do a(n,m):=(m-2)! od: od: for n from 1 to nmax do seq(a(n,m),m=1..n) od;
A165674
Triangle generated by the asymptotic expansions of the E(x,m=2,n).
Original entry on oeis.org
1, 3, 1, 11, 5, 1, 50, 26, 7, 1, 274, 154, 47, 9, 1, 1764, 1044, 342, 74, 11, 1, 13068, 8028, 2754, 638, 107, 13, 1, 109584, 69264, 24552, 5944, 1066, 146, 15, 1, 1026576, 663696, 241128, 60216, 11274, 1650, 191, 17, 1
Offset: 1
A093905 is the reversal of this triangle.
A080663, n>=2, is the third right hand column.
A094587 is generated by the asymptotic expansions of E(x, m=1, n).
-
nmax:=9; for n from 1 to nmax do a(n, n) := 1 od: for n from 2 to nmax do a(n, 1) := n*a(n-1, 1) + (n-1)! od: for n from 3 to nmax do for m from 2 to n-1 do a(n, m) := (n-m+1)*a(n-1, m) + a(n-1, m-1) od: od: seq(seq(a(n, m), m = 1..n), n = 1..nmax);
# End program 1
nmax := nmax+1: m:=2; with(combinat): EA := proc(x, m, n) local E, i; E:=0: for i from m-1 to nmax+2 do E := E + sum((-1)^(m+k1+1) * binomial(k1, m-1) * n^(k1-m+1) * stirling1(i, k1), k1=m-1..i) / x^(i-m+1) od: E:= exp(-x)/x^(m) * E: return(E); end: for n1 from 1 to nmax do f(n1-1) := simplify(exp(x) * x^(nmax+3) * EA(x, m, n1)); for m1 from 0 to nmax+2 do b(n1-1, m1) := coeff(f(n1-1), x, nmax+2-m1) od: od: for n1 from 0 to nmax-1 do for m1 from 0 to n1-m+1 do a(n1-m+2, m1+1) := abs(b(m1, n1-m1)) od: od: seq(seq(a(n, m), m = 1..n),n = 1..nmax-1);
# End program 2
# Maple programs revised by Johannes W. Meijer, Sep 22 2012
A105954
Array read by descending antidiagonals: A(n, k) = (n + 1)! * H(k, n + 1), where H(n, k) is a higher-order harmonic number, H(0, k) = 1/k and H(n, k) = Sum_{j=1..k} H(n-1, j), for 0 <= k <= n.
Original entry on oeis.org
1, 1, 1, 1, 3, 2, 1, 5, 11, 6, 1, 7, 26, 50, 24, 1, 9, 47, 154, 274, 120, 1, 11, 74, 342, 1044, 1764, 720, 1, 13, 107, 638, 2754, 8028, 13068, 5040, 1, 15, 146, 1066, 5944, 24552, 69264, 109584, 40320, 1, 17, 191, 1650, 11274, 60216, 241128, 663696, 1026576, 362880
Offset: 0
A(2, 2) = (1 + (1 + 1/2) + (1 + 1/2 + 1/3))*6 = 26.
Array A(n, k) begins:
[n\k] 0 1 2 3 4 5 6
-------------------------------------------------------------------
[0] 1, 1, 1, 1, 1, 1, 1, ...
[1] 1, 3, 5, 7, 9, 11, 13, ...
[2] 2, 11, 26, 47, 74, 107, 146, ...
[3] 6, 50, 154, 342, 638, 1066, 1650, ...
[4] 24, 274, 1044, 2754, 5944, 11274, 19524, ...
[5] 120, 1764, 8028, 24552, 60216, 127860, 245004, ...
[6] 720, 13068, 69264, 241128, 662640, 1557660, 3272688, ...
[7] 5040, 109584, 663696, 2592720, 7893840, 20355120, 46536624, ...
- G. C. Greubel, Table of n, a(n) for the first 27 rows, flattened
- Arthur T. Benjamin, David Gaebler and Robert Gaebler, A Combinatorial Approach to Hyperharmonic Numbers, INTEGERS, Electronic Journal of Combinatorial Number Theory, Volum 3, #A15, 2003.
Column 0 =
A000142 (factorial numbers).
Column 1 =
A000254 (Stirling numbers of first kind s(n, 2)) starting at n=1.
Column 2 =
A001705 (Generalized Stirling numbers: a(n) = n!*Sum_{k=0..n-1}(k+1)/(n-k)), starting at n=1.
Column 3 =
A001711 (Generalized Stirling numbers: a(n) = Sum_{k=0..n}(-1)^(n+k)*(k+1)*3^k*stirling1(n+1, k+1)).
Column 4 =
A001716 (Generalized Stirling numbers: a(n) = Sum_{k=0..n}(-1)^(n+k)*(k+1)*4^k*stirling1(n+1, k+1)).
Column 5 =
A001721 (Generalized Stirling numbers: a(n) = Sum_{k=0..n}(-1)^(n+k)*binomial(k+1, 1)*5^k*stirling1(n+1, k+1)).
2nd row is
A005408 (2n - 1, starting at n=1).
3rd row is
A080663 (3n^2 - 1, starting at n=1).
-
H := proc(n, k) option remember; if n = 0 then 1/k else add(H(n - 1, j), j = 1..k) fi end: A := (n, k) -> (n + 1)!*H(k, n + 1):
# Alternative with standard harmonic number:
A := (n, k) -> if k = 0 then n! else (harmonic(n + k) - harmonic(k - 1))*(n + k)! / (k - 1)! fi:
for n from 0 to 7 do seq(A(n, k), k = 0..6) od;
# Alternative with hypergeometric formula:
A := (n, k) -> (n+1)*((n + k)! / k!)*hypergeom([-n, 1, 1], [2, k+1], 1):
seq(print(seq(simplify(A(n, k)), k = 0..6)), n=0..7); # Peter Luschny, Jul 01 2022
-
H[0, m_] := 1/m; H[n_, m_] := Sum[H[n - 1, k], {k, m}]; a[n_, m_] := m!H[n, m]; Flatten[ Table[ a[i, n - i], {n, 10}, {i, n - 1, 0, -1}]]
Table[ a[n, m], {m, 8}, {n, 0, m + 1}] // TableForm (* to view the table *)
(* Robert G. Wilson v, Jun 27 2005 *)
-
a(n, k) = polcoef(prod(j=0, n, 1+(j+k)*x), n); \\ Seiichi Manyama, May 19 2025
A138771
Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} whose 2nd cycle has k entries; each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements (n>=1; 0<=k<=n-1). For example, 1432=(1)(24)(3) has 2 entries in the 2nd cycle; 3421=(1324) has 0 entries in the 2nd cycle.
Original entry on oeis.org
1, 1, 1, 2, 3, 1, 6, 11, 5, 2, 24, 50, 26, 14, 6, 120, 274, 154, 94, 54, 24, 720, 1764, 1044, 684, 444, 264, 120, 5040, 13068, 8028, 5508, 3828, 2568, 1560, 720, 40320, 109584, 69264, 49104, 35664, 25584, 17520, 10800, 5040
Offset: 1
T(4,2)=5 because we have (1)(23)(4), (1)(24)(3), (13)(24), (12)(34) and (14)(23).
Triangle starts;
1;
1,1;
2,3,1;
6,11,5,2;
24,50,26,14,6;
120,274,154,94,54,24;
A000142 equals for n=>1 the row sums.
(End)
-
T:=proc (n,k) if k = 0 then factorial(n-1) elif n <= k then 0 else (n-1)*T(n-1, k)+factorial(n-2) end if end proc: for n to 9 do seq(T(n, k), k=0..n-1) end do;
A203147
(n-1)-st elementary symmetric function of {11, 12, 13, 14, ..., 10 + n}.
Original entry on oeis.org
1, 23, 431, 7750, 140274, 2604744, 50046408, 998853264, 20742534576, 448372820160, 10086271796160, 235977273544320, 5737221760152960, 144817445022243840, 3791415072241843200, 102851265545431603200, 2888120485072388966400
Offset: 1
-
t[n_] := Table[k + 10, {k, 1, n}];
a[n_] := SymmetricPolynomial[n - 1, t[n]]; Table[a[n], {n, 1, 16}]
A382347
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where A(n,k) = [x^n] Product_{j=0..n} (1 + (k*n+j)*x).
Original entry on oeis.org
1, 1, 1, 1, 3, 2, 1, 5, 26, 6, 1, 7, 74, 342, 24, 1, 9, 146, 1650, 5944, 120, 1, 11, 242, 4578, 48504, 127860, 720, 1, 13, 362, 9774, 189144, 1763100, 3272688, 5040, 1, 15, 506, 17886, 520024, 9660840, 76223664, 97053936, 40320, 1, 17, 674, 29562, 1164024, 34201080, 586813968, 3817038960, 3270729600, 362880
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 3, 5, 7, 9, 11, ...
2, 26, 74, 146, 242, 362, ...
6, 342, 1650, 4578, 9774, 17886, ...
24, 5944, 48504, 189144, 520024, 1164024, ...
120, 127860, 1763100, 9660840, 34201080, 93638820, ...
-
a(n, k) = sum(j=0, n, (j+1)*(k*n)^j*abs(stirling(n+1, j+1, 1)));
A384024
a(n) = [x^n] Product_{k=0..n} (1 + (n+k)*x).
Original entry on oeis.org
1, 3, 26, 342, 5944, 127860, 3272688, 97053936, 3270729600, 123418922400, 5154170774400, 235977273544320, 11752173128586240, 632474276804697600, 36576553723886131200, 2261980049125982976000, 148956705206745595084800, 10406288081667512679321600, 768701832940487804295168000
Offset: 0
-
Table[SeriesCoefficient[Product[1 + (n+k)*x, {k, 0, n}], {x, 0, n}], {n, 0, 20}]
-
a(n) = sum(k=0, n, (k+1)*n^k*abs(stirling(n+1, k+1, 1))); \\ Seiichi Manyama, May 18 2025
A093345
a(n) = n! * {1 + Sum[i=1..n, 1/i*Sum(j=0..i-1, 1/j!)]}.
Original entry on oeis.org
1, 2, 6, 23, 108, 605, 3956, 29649, 250892, 2367629, 24662700, 281153801, 3482350724, 46572620757, 668943488084, 10271127486065, 167892667249116, 2911049382788189, 53365747562592092, 1031352659792534169
Offset: 0
-
a[n_] := n! (1+Sum[1/i Sum[1/j!, {j, 0, i-1}], {i, 1, n}])
Table[a[n], {n, 0, 19}] (* Jean-François Alcover, Oct 05 2018 *)
-
a(n)=n!+n!*sum(i=1,n,1/i*sum(j=0,i-1,1/j!))
A203239
Odd numbered terms of the sequence whose n-th term is the (n-1)-st elementary symmetric function of (i, 2i, 3i, ..., ni), where i=sqrt(-1).
Original entry on oeis.org
3, -50, 1764, -109584, 10628640, -1486442880, 283465647360, -70734282393600, 22376988058521600, -8752948036761600000, 4148476779335454720000, -2342787216398718566400000, 1554454559147562279567360000
Offset: 1
The first 10 terms of the "full sequence" are as follows:
1, 3i, -11, -50i, 274, 1764i, -13068, -109584i, 1026576, 10628640i;
Abbreviate "elementary symmetric function" as esf. Then, starting with {i, 2i, 3i, 4i, ...}:
0th esf of {i}: 1
1st esf of {i, 2i}: i+2i = 3i
2nd esf of {i, 2i, 3i}: -2-3-6 = -11.
For the alternating terms 3i, -50i, ..., see A203240.
-
f[k_] := k*I; t[n_] := Table[f[k], {k, 1, n}]
a[n_] := SymmetricPolynomial[n - 1, t[n]]
Table[a[n], {n, 1, 22}]
Table[-I*a[2 n], {n, 1, 22}] (* A203239 *)
Table[a[2 n - 1], {n, 1, 22}] (* A203240 *)
Table[(-1)^(n + 1)*(2*n)!*HarmonicNumber[2*n], {n, 13}] (* Arkadiusz Wesolowski, Mar 25 2013 *)
A382349
a(n) = [x^n] Product_{k=0..n} (1 + (3*n+k)*x).
Original entry on oeis.org
1, 7, 146, 4578, 189144, 9660840, 586813968, 41283943344, 3299858098560, 295294500123840, 29242449106502400, 3174506423754019200, 374845813851886709760, 47828682507084551654400, 6557612642418946942310400, 961431335221085133398784000, 150095351600371197275428454400
Offset: 0
-
Table[SeriesCoefficient[Product[(1 + (3*n+k)*x), {k, 0, n}], {x, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, May 23 2025 *)
-
a(n) = sum(k=0, n, (k+1)*(3*n)^k*abs(stirling(n+1, k+1, 1)));
Showing 1-10 of 12 results.
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