A007758
a(n) = 2^n*n^2.
Original entry on oeis.org
0, 2, 16, 72, 256, 800, 2304, 6272, 16384, 41472, 102400, 247808, 589824, 1384448, 3211264, 7372800, 16777216, 37879808, 84934656, 189267968, 419430400, 924844032, 2030043136, 4437573632, 9663676416, 20971520000, 45365592064, 97844723712, 210453397504
Offset: 0
David J. Snook (ua532(AT)freenet.victoria.bc.ca)
- Arno Berger and Theodore P. Hill. An Introduction to Benford's Law. Princeton University Press, 2015.
- Konrad Knopp, Theory and Application of Infinite Series, Dover, p. 269.
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Konrad Knopp, Theorie und Anwendung der unendlichen Reihen, Berlin, J. Springer, 1922. (Original german edition of "Theory and Application of Infinite Series")
- Wikipedia, Complexity.
- Index entries for linear recurrences with constant coefficients, signature (6,-12,8).
- Index entries for sequences related to Benford's law.
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[2^n*n^2: n in [0..30]]; // Vincenzo Librandi, Oct 27 2011
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seq(seq(k^n*n^k, k=2..2), n=0..25); and seq(2^n*n^2, n=0..25); # Zerinvary Lajos, Jul 01 2007
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Table[n^2 * 2^n, {n, 0, 31}] (* Alonso del Arte, Oct 22 2014 *)
LinearRecurrence[{6,-12,8},{0,2,16},30] (* Harvey P. Dale, Jan 27 2017 *)
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a(n)=n^2<Charles R Greathouse IV, Oct 28 2014
A118416
Triangle read by rows: T(n,k) = (2*k-1)*2^(n-1), 0 < k <= n.
Original entry on oeis.org
1, 2, 6, 4, 12, 20, 8, 24, 40, 56, 16, 48, 80, 112, 144, 32, 96, 160, 224, 288, 352, 64, 192, 320, 448, 576, 704, 832, 128, 384, 640, 896, 1152, 1408, 1664, 1920, 256, 768, 1280, 1792, 2304, 2816, 3328, 3840, 4352, 512, 1536, 2560, 3584, 4608, 5632, 6656, 7680
Offset: 1
Triangle begins:
1;
2, 6;
4, 12, 20;
8, 24, 40, 56;
16, 48, 80, 112, 144;
32, 96, 160, 224, 288, 352;
64, 192, 320, 448, 576, 704, 832;
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a118416 n k = a118416_tabl !! (n-1) !! (k-1)
a118416_row 1 = [1]
a118416_row n = (map (* 2) $ a118416_row (n-1)) ++ [a014480 (n-1)]
a118416_tabl = map a118416_row [1..]
-- Reinhard Zumkeller, Jan 22 2012
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A118416 := proc(n,k) 2^(n-1)*(2*k-1) ; end proc: # R. J. Mathar, Sep 04 2011
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Flatten[Table[(2k-1)2^(n-1),{n,10},{k,n}]] (* Harvey P. Dale, Aug 26 2014 *)
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from math import isqrt
def A118416(n): return (a:=(m:=isqrt(k:=n<<1))+(k>m*(m+1)))*(1-a)+(n<<1)-1<Chai Wah Wu, Jun 20 2025
A014479
Exponential generating function = (1+2*x)/(1-2*x)^3.
Original entry on oeis.org
1, 8, 72, 768, 9600, 138240, 2257920, 41287680, 836075520, 18579456000, 449622835200, 11771943321600, 331576403558400, 9998303861145600, 321374052679680000, 10969567664799744000, 396275631890890752000
Offset: 0
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seq(add(count(Composition(k))*count(Permutation(k)),k=1..n),n=1..17); # Zerinvary Lajos, Oct 17 2006
seq(2^n*(n+1)^2*n!, n=0..30); # Robert Israel, Oct 28 2015
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Table[2^n (n+1)^2 n!, {n, 0, 20}] (* Vladimir Reshetnikov, Oct 28 2015 *)
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{a(n)=polcoeff( sum(m=0,n,(2*m+1)^(m+1)*x^m / (1 + (2*m+1)*x +x*O(x^n))^(m+1)),n)} \\ Paul D. Hanna, Jan 02 2013
for(n=0,20,print1(a(n),", "))
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vector(30, n, n--; n!*(n+1)^2*2^n) \\ Altug Alkan, Oct 28 2015
Original entry on oeis.org
0, 1, 9, 45, 173, 573, 1725, 4861, 13053, 33789, 84989, 208893, 503805, 1196029, 2801661, 6488061, 14876669, 33816573, 76283901, 170917885, 380633085, 843055101, 1858076669, 4076863485, 8908701693, 19394461693, 42077257725, 90999619581, 196226318333
Offset: 0
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m:=28; R:=PowerSeriesRing(Integers(), m); [0] cat Coefficients(R!((1+2*x)/((1-x)*(1-2*x)^3))); // Bruno Berselli, Mar 06 2012
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A036826:= n-> 2^n*(3-2*n+n^2) -3; seq(A036826(n), n=0..30); # G. C. Greubel, Mar 31 2021
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LinearRecurrence[{7,-18,20,-8}, {0,1,9,45}, 29] (* Bruno Berselli, Mar 06 2012 *)
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for(n=0, 28, print1(2^n*(n^2-2*n+3)-3", ")); \\ Bruno Berselli, Mar 06 2012
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[2^n*(3-2*n+n^2) -3 for n in (0..30)] # G. C. Greubel, Mar 31 2021
A118414
a(n) = (2*n - 1) * (2^n - 1).
Original entry on oeis.org
1, 9, 35, 105, 279, 693, 1651, 3825, 8687, 19437, 42987, 94185, 204775, 442341, 950243, 2031585, 4325343, 9175005, 19398619, 40894425, 85983191, 180355029, 377487315, 788529105, 1644167119, 3422552013, 7113539531, 14763950025, 30601641927, 63350767557, 130996502467, 270582939585
Offset: 1
The triangle T(r,c) for n=4 has row(1)=7; row(2) = 5, 9; row(3) = 3, 14, 11; row(4) = 1, 17, 25, 13, and a sum of 7+5+9+...+13 = 105 = a(4). - _J. M. Bergot_, Oct 12 2012
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[(2*n-1)*(2^n-1): n in [1..40]]; // Vincenzo Librandi, Dec 26 2010
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Table[(2 n - 1) (2^n - 1), {n, 32}] (* or *)
Rest@ CoefficientList[Series[-x (-1 - 3 x + 6 x^2)/((2 x - 1)^2*(x - 1)^2), {x, 0, 32}], x] (* Michael De Vlieger, Sep 26 2016 *)
LinearRecurrence[{6,-13,12,-4},{1,9,35,105},40] (* Harvey P. Dale, Sep 12 2023 *)
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a(n)=(2*n-1)*(2^n-1) \\ Charles R Greathouse IV, Oct 12 2012
A086603
a(n) = n^3*3^(n-1).
Original entry on oeis.org
0, 1, 24, 243, 1728, 10125, 52488, 250047, 1119744, 4782969, 19683000, 78594219, 306110016, 1167575877, 4374822312, 16142520375, 58773123072, 211488540273, 753145430616, 2657317134051, 9298091736000, 32291110337661
Offset: 0
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List([0..30], n-> 3^(n-1)*n^3 ); # G. C. Greubel, Feb 08 2020
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[3^(n-1)*n^3: n in [0..30]]; // G. C. Greubel, Feb 08 2020
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seq( 3^(n-1)*n^3, n=0..30); # G. C. Greubel, Feb 08 2020
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Table[n^3 3^(n-1),{n,0,30}] (* Harvey P. Dale, Mar 12 2011 *)
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vector(31, n, my(m=n-1); 3^(m-1)*m^3) \\ G. C. Greubel, Feb 08 2020
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[3^(n-1)*n^3 for n in (0..30)] # G. C. Greubel, Feb 08 2020
A141692
Triangle read by rows: T(n,k) = n*(binomial(n - 1, k - 1) - binomial(n - 1, k)), 0 <= k <= n.
Original entry on oeis.org
0, -1, 1, -2, 0, 2, -3, -3, 3, 3, -4, -8, 0, 8, 4, -5, -15, -10, 10, 15, 5, -6, -24, -30, 0, 30, 24, 6, -7, -35, -63, -35, 35, 63, 35, 7, -8, -48, -112, -112, 0, 112, 112, 48, 8, -9, -63, -180, -252, -126, 126, 252, 180, 63, 9, -10, -80, -270, -480, -420, 0, 420, 480, 270, 80, 10
Offset: 0
Triangle begins:
0;
-1, 1;
-2, 0, 2;
-3, -3, 3, 3;
-4, -8, 0, 8, 4;
-5, -15, -10, 10, 15, 5;
-6, -24, -30, 0, 30, 24, 6;
-7, -35, -63, -35, 35, 63, 35, 7;
-8, -48, -112, -112, 0, 112, 112, 48, 8;
-9, -63, -180, -252, -126, 126, 252, 180, 63, 9;
-10, -80, -270, -480, -420, 0, 420, 480, 270, 80, 10;
...
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a:=proc(n,k) n*(binomial(n-1,k-1)-binomial(n-1,k)); end proc: seq(seq(a(n,k),k=0..n),n=0..10); # Muniru A Asiru, Oct 03 2018
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Table[Table[n*(Binomial[n - 1, k - 1] - Binomial[n - 1, k]),{k, 0, n}],{n, 0, 12}]//Flatten
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T(n, k) := n*(binomial(n - 1, k - 1) - binomial(n - 1, k))$
tabl(nn) := for n:0 thru nn do print(makelist(T(n, k), k, 0, n))$ /* Franck Maminirina Ramaharo, Oct 02 2018 */
A152548
Sum of squared terms in rows of triangle A152547: a(n) = Sum_{k=0..C(n,[n/2])-1} A152547(n,k)^2.
Original entry on oeis.org
1, 4, 10, 24, 54, 120, 260, 560, 1190, 2520, 5292, 11088, 23100, 48048, 99528, 205920, 424710, 875160, 1798940, 3695120, 7574996, 15519504, 31744440, 64899744, 132503644, 270415600, 551231800, 1123264800, 2286646200, 4653525600
Offset: 0
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seq(simplify((-2)^n*hypergeom([-n,3/2], [1], 2)),n=0..29); # Peter Luschny, Apr 26 2016
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CoefficientList[Series[Sqrt[(1+2x)/(1-2x)^3],{x,0,30}],x] (* Harvey P. Dale, Jan 04 2016 *)
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a(n)=sum(k=0,floor((n+1)/2),binomial(n+1, k)*(n+1-2*k)^3)/(n+1)
A084850
2^(n-1)*(n^2+2n+2).
Original entry on oeis.org
1, 5, 20, 68, 208, 592, 1600, 4160, 10496, 25856, 62464, 148480, 348160, 806912, 1851392, 4210688, 9502720, 21299200, 47448064, 105119744, 231735296, 508559360, 1111490560, 2420113408, 5251268608, 11358175232, 24494735360
Offset: 0
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LinearRecurrence[{6,-12,8},{1,5,20},40] (* Harvey P. Dale, Mar 15 2016 *)
A135065
A127733 * A007318 as infinite lower triangular matrices.
Original entry on oeis.org
1, 4, 4, 9, 18, 9, 16, 48, 48, 16, 25, 100, 150, 100, 25, 36, 180, 360, 360, 180, 36, 49, 294, 735, 980, 735, 294, 49, 64, 448, 1344, 2240, 2240, 1344, 448, 64, 81, 648, 2268, 4536, 5670, 4536, 2268, 648, 81, 100, 900, 3600, 8400, 12600, 12600, 8400, 3600
Offset: 0
First few rows of the triangle:
1;
4, 4;
9, 18, 9;
16, 48, 48, 16;
25, 100, 150, 100, 25;
36, 180, 360, 360, 180, 36;
49, 294, 735, 980, 735, 294, 49;
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with(combstruct):for n from 0 to 11 do seq(n*m*count(Combination(n), size=m), m = 1 .. n) od; # Zerinvary Lajos, Apr 09 2008
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Flatten[Table[Binomial[n,k](n+1)^2,{n,0,10},{k,0,n}]] (* Harvey P. Dale, Jul 12 2013 *)
Showing 1-10 of 14 results.
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