A047916
Triangular array read by rows: a(n,k) = phi(n/k)*(n/k)^k*k! if k|n else 0 (1<=k<=n).
Original entry on oeis.org
1, 2, 2, 6, 0, 6, 8, 8, 0, 24, 20, 0, 0, 0, 120, 12, 36, 48, 0, 0, 720, 42, 0, 0, 0, 0, 0, 5040, 32, 64, 0, 384, 0, 0, 0, 40320, 54, 0, 324, 0, 0, 0, 0, 0, 362880, 40, 200, 0, 0, 3840, 0, 0, 0, 0, 3628800, 110, 0, 0, 0, 0, 0, 0, 0, 0, 0, 39916800, 48, 144
Offset: 1
1; 2,2; 6,0,6; 8,8,0,24; 20,0,0,0,120; 12,36,48,0,0,720; ...
- J. E. A. Steggall, On the numbers of patterns which can be derived from certain elements, Mess. Math., 37 (1907), 56-61.
- Reinhard Zumkeller, Rows n = 1..125 of triangle, flattened
- C. L. Mallows and N. J. A. Sloane, Notes on A002618, A002619, etc.
- N. J. A. Sloane, Notes on A002618, A002619, etc.
- J. E. A. Steggall, On the numbers of patterns which can be derived from certain elements, Mess. Math., 37 (1907), 56-61.
- J. E. A. Steggall, On the numbers of patterns which can be derived from certain elements, Mess. Math., 37 (1907), 56-61. [Annotated scanned copy. Note that the scanned pages are out of order]
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import Data.List (zipWith4)
a047916 n k = a047916_tabl !! (n-1) !! (k-1)
a047916_row n = a047916_tabl !! (n-1)
a047916_tabl = zipWith4 (zipWith4 (\x u v w -> x * v ^ u * w))
a054523_tabl a002260_tabl a010766_tabl a166350_tabl
-- Reinhard Zumkeller, Jan 20 2014
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a[n_, k_] := If[Divisible[n, k], EulerPhi[n/k]*(n/k)^k*k!, 0]; Flatten[ Table[ a[n, k], {n, 1, 12}, {k, 1, n}]] (* Jean-François Alcover, May 04 2012 *)
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a(n,k)=if(n%k, 0, eulerphi(n/k)*(n/k)^k*k!) \\ Charles R Greathouse IV, Feb 09 2017
A269221
Factorial of the sum of decimal digits of n.
Original entry on oeis.org
1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 24, 120, 720, 5040
Offset: 0
A288777
Triangle read by rows in which column k lists the positive multiples of the factorial of k, with 1 <= k <= n.
Original entry on oeis.org
1, 2, 2, 3, 4, 6, 4, 6, 12, 24, 5, 8, 18, 48, 120, 6, 10, 24, 72, 240, 720, 7, 12, 30, 96, 360, 1440, 5040, 8, 14, 36, 120, 480, 2160, 10080, 40320, 9, 16, 42, 144, 600, 2880, 15120, 80640, 362880, 10, 18, 48, 168, 720, 3600, 20160, 120960, 725760, 3628800, 11, 20, 54, 192, 840, 4320, 25200, 161280, 1088640
Offset: 1
Triangle begins:
1;
2, 2;
3, 4, 6;
4, 6, 12, 24;
5, 8, 18, 48, 120;
6, 10, 24, 72, 240, 720;
7, 12, 30, 96, 360, 1440, 5040;
8, 14, 36, 120, 480, 2160, 10080, 40320;
9, 16, 42, 144, 600, 2880, 15120, 80640, 362880;
10, 18, 48, 168, 720, 3600, 20160, 120960, 725760, 3628800;
11, 20, 54, 192, 840, 4320, 25200, 161280, 1088640, 7257600, 39916800;
...
For n = 9 and k = 2: T(9,2) is the number of numbers with two digits in A288528.
For n = 9 the row sum is 9 + 16 + 42 + 144 + 600 + 2880 + 15120 + 80640 + 362880 = 462331, the same as A014145(9) and also the same as the number of terms in A288528.
Middle diagonal gives
A001563, n>=1.
Original entry on oeis.org
0, 1, 2, 5, 6, 21, 22, 73, 210, 1693, 1694, 2097, 2098, 12997, 21468, 174169, 174170, 1986237, 1986238, 10178833, 16875654, 246551437, 246551438, 2032266537, 3767596738, 45445808989, 260705796192, 2932954933753, 2932954933754, 5496591783573, 5496591783574
Offset: 1
a(5) = gcd(1!,5!)+gcd(2!,3*4*5)+gcd(3!,4*5)+gcd(4!,5)=1+2+2+1 = 6.
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a014454 n = sum $ zipWith gcd kfs $ map (div nf) kfs
where (nf:kfs) = reverse $ a166350_row n
-- Reinhard Zumkeller, Nov 11 2013
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a(n) = sum(k=1, n-1, gcd(k!, n!/k!)); \\ Michel Marcus, Aug 04 2013
A269223
Factorial of the sum of digits of n in base 3.
Original entry on oeis.org
1, 1, 2, 1, 2, 6, 2, 6, 24, 1, 2, 6, 2, 6, 24, 6, 24, 120, 2, 6, 24, 6, 24, 120, 24, 120, 720, 1, 2, 6, 2, 6, 24, 6, 24, 120, 2, 6, 24, 6, 24, 120, 24, 120, 720, 6, 24, 120, 24, 120, 720, 120, 720, 5040, 2, 6, 24, 6, 24, 120, 24, 120, 720, 6, 24, 120, 24, 120, 720, 120, 720
Offset: 0
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Table[Total[IntegerDigits[n, 3]]!, {n, 0, 70}] (* Michael De Vlieger, Mar 15 2016 *)
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A269223(n)=sumdigits(n,3)! \\ sumdigits(.,3) requires version > 2.7.1; see A053735 for a substitute.
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a(n) = vecsum(digits(n,3))!; \\ Michel Marcus, Mar 15 2016
A288778
Triangle read by rows (1<=k<=n): T(n,k) = (n-k+1)*k! - (k-1)!
Original entry on oeis.org
0, 1, 1, 2, 3, 4, 3, 5, 10, 18, 4, 7, 16, 42, 96, 5, 9, 22, 66, 216, 600, 6, 11, 28, 90, 336, 1320, 4320, 7, 13, 34, 114, 456, 2040, 9360, 35280, 8, 15, 40, 138, 576, 2760, 14400, 75600, 322560, 9, 17, 46, 162, 696, 3480, 19440, 115920, 685440, 3265920, 10, 19, 52, 186, 816, 4200, 24480, 156240, 1048320, 6894720, 36288000
Offset: 1
Triangle begins:
0;
1, 1;
2, 3, 4;
3, 5, 10, 18;
4, 7, 16, 42, 96;
5, 9, 22, 66, 216, 600;
6, 11, 28, 90, 336, 1320, 4320;
7, 13, 34, 114, 456, 2040, 9360, 35280;
8, 15, 40, 138, 576, 2760, 14400, 75600, 322560;
9, 17, 46, 162, 696, 3480, 19440, 115920, 685440, 3265920;
10, 19, 52, 186, 816, 4200, 24480, 156240, 1048320, 6894720, 36288000;
...
For n = 10 and k = 2; T(10,2) = 17 coincides with the number of positive terms with two digits in A215014 (see the first comment above).
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Table[(n - k + 1) k! - (k - 1)!, {n, 11}, {k, n}] // Flatten (* Michael De Vlieger, Jun 16 2017 *)
A256589
Triangle read by rows: T(n,k) divided by (n-k+1)! is the expected value of number of possible subsets in a partition of a set of n elements with no subsets of cardinality smaller than k.
Original entry on oeis.org
1, 3, 1, 11, 2, 1, 50, 8, 2, 1, 274, 36, 6, 2, 1, 1764, 200, 30, 6, 2, 1, 13068, 1300, 168, 24, 6, 2, 1, 109584, 9720, 1080, 144, 24, 6, 2, 1, 1026576, 82180, 8100, 960, 120, 24, 6, 2, 1
Offset: 1
The triangle T(n, k) starts:
n\k 1 2 3 4 5 6 ...
1: 1
2: 3 1
3: 11 2 1
4: 50 8 2 1
5: 274 36 6 2 1
6:1764 200 36 6 2 1
A269224
Factorial of the sum of digits of n in base 4.
Original entry on oeis.org
1, 1, 2, 6, 1, 2, 6, 24, 2, 6, 24, 120, 6, 24, 120, 720, 1, 2, 6, 24, 2, 6, 24, 120, 6, 24, 120, 720, 24, 120, 720, 5040, 2, 6, 24, 120, 6, 24, 120, 720, 24, 120, 720, 5040, 120, 720, 5040, 40320, 6, 24, 120, 720, 24, 120, 720, 5040, 120, 720, 5040, 40320, 720, 5040, 40320
Offset: 0
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Table[Total[IntegerDigits[n, 4]]!, {n, 0, 62}] (* Michael De Vlieger, Mar 15 2016 *)
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A269224(n)=sumdigits(n,4)! \\ sumdigits(.,4) requires version >= 2.7; see A053737 for a substitute.
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a(n) = vecsum(digits(n,4))!; \\ Michel Marcus, Mar 15 2016
A233543
Triangle read by rows: T(n,k) = k!.
Original entry on oeis.org
1, 1, 1, 1, 1, 2, 1, 1, 2, 6, 1, 1, 2, 6, 24, 1, 1, 2, 6, 24, 120, 1, 1, 2, 6, 24, 120, 720, 1, 1, 2, 6, 24, 120, 720, 5040, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800
Offset: 0
Triangle begins:
1;
1, 1;
1, 1, 2;
1, 1, 2, 6;
1, 1, 2, 6, 24;
1, 1, 2, 6, 24, 120;
...
Showing 1-9 of 9 results.
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