A152691 -id:A152691 - cp's OEIS frontend

A174312 a(n) = 32*n.

0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704, 736, 768, 800, 832, 864, 896, 928, 960, 992, 1024, 1056, 1088, 1120, 1152, 1184, 1216, 1248, 1280, 1312, 1344, 1376, 1408, 1440, 1472, 1504, 1536, 1568, 1600

Offset: 0

Paul Curtz, Nov 27 2010

Subsequence of squares is A017066 (see 2nd formula). - Bernard Schott, Mar 03 2023

Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1).

Cf. A001105, A008598, A017066, A135628, A135631, A152691.

[32*n: n in [0..60]]; // Vincenzo Librandi, Aug 04 2011

Range[0, 3000, 32] (* Vladimir Joseph Stephan Orlovsky, Jun 03 2011 *)

a(n)=n<<5 \\ Charles R Greathouse IV, Dec 21 2011

G.f.: 32*x/(1-x)^2.
a(A001105(n)) = A017066(n). - Bernard Schott, Mar 05 2023
From Elmo R. Oliveira, Apr 07 2025: (Start)
E.g.f.: 32*x*exp(x).
a(n) = 2*A008598(n) = A152691(n)/2.
a(n) = 2*a(n-1) - a(n-2). (End)

A017066 a(n) = (8*n)^2.

Original entry on oeis.org

0, 64, 256, 576, 1024, 1600, 2304, 3136, 4096, 5184, 6400, 7744, 9216, 10816, 12544, 14400, 16384, 18496, 20736, 23104, 25600, 28224, 30976, 33856, 36864, 40000, 43264, 46656, 50176, 53824, 57600, 61504, 65536, 69696, 73984, 78400, 82944, 87616, 92416, 97344, 102400

Offset: 0

N. J. A. Sloane

Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A000290, A008590, A016802, A152691, A244082.

[(8*n)^2: n in [0..35]]; // Vincenzo Librandi, Jul 10 2011

LinearRecurrence[{3, -3, 1}, {0, 64, 256}, 50] (* Vincenzo Librandi, Feb 10 2012 *)

a(n)=(8*n)^2 \\ Charles R Greathouse IV, Jun 17 2017

G.f.: -64*x*(1+x)/(x-1)^3. - R. J. Mathar, Jul 14 2016
a(n) = A000290(8*n) = A008590(n)^2 = A000290(A008590(n)).
From Amiram Eldar, Jan 25 2021: (Start)
Sum_{n>=1} 1/a(n) = Pi^2/384.
Sum_{n>=1} (-1)^(n+1)/a(n) = Pi^2/768.
Product_{n>=1} (1 + 1/a(n)) = sinh(Pi/8)/(Pi/8).
Product_{n>=1} (1 - 1/a(n)) = sin(Pi/8)/(Pi/8) = 4*sqrt(2-sqrt(2))/Pi. (End)
From Elmo R. Oliveira, Dec 06 2024: (Start)
E.g.f.: 64*exp(x)*x*(1 + x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2.
a(n) = n*A152691(n) = 2*A244082(n) = A016802(2*n). (End)

A305548 a(n) = 27*n.

Original entry on oeis.org

0, 27, 54, 81, 108, 135, 162, 189, 216, 243, 270, 297, 324, 351, 378, 405, 432, 459, 486, 513, 540, 567, 594, 621, 648, 675, 702, 729, 756, 783, 810, 837, 864, 891, 918, 945, 972, 999, 1026, 1053, 1080, 1107, 1134, 1161, 1188, 1215, 1242, 1269, 1296, 1323, 1350, 1377, 1404, 1431, 1458, 1485, 1512

Offset: 0

Eric Chen, Jun 05 2018

Eric Chen, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1).

For a(n) = k*n: A001489 (k=-1), A000004 (k=0), A001477 (k=1), A005843 (k=2), A008585 (k=3), A008591 (k=9), A008607 (k=25), A252994 (k=26), this sequence (k=27), A135628 (k=28), A195819 (k=29), A249674 (k=30), A135631 (k=31), A174312 (k=32), A044102 (k=36), A085959 (k=37), A169823 (k=60), A152691 (k=64).

Mathematica
```
Range[0,2000,27]
```
PARI
```
a(n)=27*n
```

a(n) = 27*n.
a(n) = A008585(A008591(n)) = A008591(A008585(n)).
G.f.: 27*x/(x-1)^2.
From Elmo R. Oliveira, Apr 10 2025: (Start)
E.g.f.: 27*x*exp(x).
a(n) = 2*a(n-1) - a(n-2). (End)

A152692 a(n) = n3^n - n2^n - n*1^n.

Original entry on oeis.org

0, 0, 8, 54, 256, 1050, 3984, 14406, 50432, 172530, 580240, 1926078, 6328128, 20619690, 66732176, 214742070, 687698944, 2193154530, 6968850192, 22073006382, 69714716480, 219623377050, 690291036688, 2165100175014

Offset: 0

Vladimir Joseph Stephan Orlovsky, Dec 10 2008

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Cf. A152691.

[n*3^n-n*2^n-n*1^n: n in [0..30]]; // Vincenzo Librandi, Sep 05 2011

Table[n(3^n-2^n-1),{n,0,30}] (* Harvey P. Dale, Oct 20 2013 *)
CoefficientList[Series[-(2 x^2 (-4 + 21 x - 36 x^2 + 21 x^3))/(-1 + 6 x - 11 x^2 + 6 x^3)^2, {x, 0, 50}], x] (* Stefano Spezia, Sep 04 2018 *)

vector(30, n, n--; n*(3^n-2^n-1)) \\ G. C. Greubel, Sep 02 2018

From R. J. Mathar, Dec 12 2008: (Start)
a(n) = (-1)^(n+1)*n*A083321(n).
G.f.: 2*x^2*(4-21*x+36*x^2-21*x^3)/((1-x)^2*(1-3*x)^2*(1-2*x)^2). (End)
E.g.f.: x*(3*exp(3*x) - 2*exp(2*x) - exp(x)). - G. C. Greubel, Sep 02 2018

Offset changed from 1 to 0 by Vincenzo Librandi, Sep 05 2011

A158067 a(n) = 64n^2 - 2n.

Original entry on oeis.org

62, 252, 570, 1016, 1590, 2292, 3122, 4080, 5166, 6380, 7722, 9192, 10790, 12516, 14370, 16352, 18462, 20700, 23066, 25560, 28182, 30932, 33810, 36816, 39950, 43212, 46602, 50120, 53766, 57540, 61442, 65472, 69630, 73916, 78330, 82872

Offset: 1

Vincenzo Librandi, Mar 12 2009

The identity (64*n - 1)^2 - (64*n^2 - 2*n)*8^2 = 1 can be written as (A152691(n+1) - 1)^2 - a(n)*8^2 = 1. - Vincenzo Librandi, Feb 11 2012

Vincenzo Librandi, Table of n, a(n) for n = 1..10000
E. J. Barbeau, Polynomial Excursions, Chapter 10: Diophantine equations (2010), pages 84-85 (row 15 in the first table at p. 85, case d(t) = t*(8^2*t-2)).
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A152691.

Magma
```
[64*n^2 - 2*n: n in [1..50]]
```

LinearRecurrence[{3, -3, 1}, {62, 252, 570}, 50] (* Vincenzo Librandi, Feb 11 2012 *)
Table[64n^2-2n,{n,40}] (* Harvey P. Dale, Nov 27 2024 *)

for(n=1, 50, print1(64*n^2 - 2*n ", ")); \\ Vincenzo Librandi, Feb 11 2012

G.f.: x*(-62 - 66*x)/(x-1)^3. - Vincenzo Librandi, Feb 11 2012

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Feb 11 2012

A327916 Triangle T(k, n) read by rows: Array A(k, n) = 2^k(k + 1 + 2n), k >= 0, n >= 0, read by antidiagonals upwards.

Original entry on oeis.org

1, 4, 3, 12, 8, 5, 32, 20, 12, 7, 80, 48, 28, 16, 9, 192, 112, 64, 36, 20, 11, 448, 256, 144, 80, 44, 24, 13, 1024, 576, 320, 176, 96, 52, 28, 15, 2304, 1280, 704, 384, 208, 112, 60, 32, 17, 5120, 2816, 1536, 832, 448, 240, 128, 68, 36, 19, 11264, 6144, 3328, 1792, 960, 512, 272, 144, 76, 40, 21

Offset: 0

Wolfdieter Lang, Oct 03 2019

The array A(k, n) arises from the following Pascal-type triangles PTodd(k), k >= 0 based on the positive odd integers A005408.
For example, the Pascal-type triangle PTodd(k), for k = 3 is
   1     3     5     7
      4     8    12
        12    20
           32
Taken upside-down such triangles become so-called addition towers of height k+1 (Rechenturm in German elementary schools; thanks to my correspondent Bennet D.), starting with any k+1 numbers. Here the positive odd numbers are used.
The sequence s of the final number of these Pascal-type triangles PT(k), for k >= 0, begins 1, 4, 12, 32, ...; s(k) = (k+1)*2^k = A001787(k+1), for k >= 0.
For k -> infinity the left-aligned row sequences build the array A(k, n), with k >= 0 and n >= 0, namely A(k, n) = 2^k*(k + 2*n + 1); this array begins:
  k\n  0   1   2   3   4    5 ...
  -------------------------------
  0:   1   3   5   7   9   11 ... {A005408(n)}
  1:   4   8  12  16  20   24 ... {A008586(n+1)}
  2:  12  20  28  36  44   52 ... {A017113(n+1)}
  3:  32  48  64  80  96  112 ... {A008598(n+2)}
  4:  80 112 144 176 208  240 ... {16*A005408(n+2)}
  5: 192 256 320 384 448  512 ... {A152691(n+3)}
  6: 448 576 704 832 960 1088 ... {64*A005408(n+3)}
  ...
The sequence s, the first (n=0) column of A, is always the binomial transform of the first (k=0) row in A.
A(k, n) = Sum_{j=0..k} binomial(k, j)*(2*(n+j)+1) = 2^k*(k + 1 + 2*n), for k >= 0 and n >= 0.
The corresponding antidiagonal-upwards read triangle is T(k, n) = A(k-n, n) = 2^(k-n)*(k + n + 1), n >= 0, k = 0..n.
If the nonnegative integers A001477 are used as k = 0 row of the array Anneg(k, n) = 2^(k-1)*(2*n + k), for k >= 0, n >= 0, with the triangle Tnneg(k, n) = Anneg(k-n, n) = (n + k)*2^(k-n-1), k >= 0, n = 0..k, then the s sequence is snneg(k) = Tnneg(k, 0) = k*2^{k-1} = A001787(k), the binomial transform of the sequence{A001477(n)}_{n>=0}. The triangle Tnneg begins [0], [1, 1], [4, 3, 2], [12, 8, 5, 3], [32, 20, 12, 7, 4], ... . See A062111 and the row-reversed triangle A152920 for other versions.

			The triangle T(k, n) begins:
   k\n    0    1    2    3   4   5   6   7  8  9 10 ...
  -----------------------------------------------------
   0:     1
   1:     4    3
   2:    12    8    5
   3:    32   20   12    7
   4:    80   48   28   16   9
   5:   192  112   64   36  20  11
   6:   448  256  144   80  44  24  13
   7:  1024  576  320  176  96  52  28  15
   8:  2304 1280  704  384 208 112  60  32 17
   9:  5120 2816 1536  832 448 240 128  68 36 19
  10: 11264 6144 3328 1792 960 512 272 144 76 40 21
  ...

Column sequences without leading zeros are for n=0..9: A001787(n+1), A001792(n+1), A045623(n+2), A045891(n+3), A034007(n+4), A111297(n+3), A159694(n+1), A159695(n+1), A159696(n+1), A159697(n+1).
The sequence of (sub)diagonal k, for k >= 0, is the row k sequence of array A: {(k + 2*n + 1)*2^k}_{k >= 0}.
Row sums: A213569(k+1), k >= 0 (see the J. M. Bergot comments there).
Cf. A006211, A152920.

Table[2^#*(# + 1 + 2 n) &[k - n], {k, 0, 10}, {n, 0, k}] // Flatten (* Michael De Vlieger, Oct 03 2019 *)

Array A(k, n) = Sum_{j=0..k} binomial(k, j)*(2*(n+j) + 1) = 2^k*(k + 1+ 2*n), for k >= 0 and n >= 0.
Triangle T(k, n) =  A(k-n, n) = 2^(k-n)*(k + n + 1), n >= 0, k = 0..n.
Recurrence: T(k, 0) = (k+1)*2^k = A001787(k+1), for k >= 0, and  T(k, n) = T(k, n-1) - T(k-1, n-1), for n >= 1, k >= 1, with T(k, n) = 0 if k < n.
O.g.f. for row polynomials: G(z,x) = Sum_{n=0..k} R(k, x)*z^n =
(1  + x*z*(1 - 4*z))/((1 - 2*z)^2*(1 - x*z)^2).
T(k, 0) = Sum_{n=0..k} binomial(k,n)*T(n, n), k >= 0 (binomial transform).

Definition corrected by Georg Fischer, Jul 13 2023

A346514 a(n) = n^4 + 28n^3 + 252n^2 + 784*n + 448.

Original entry on oeis.org

448, 1513, 3264, 5905, 9664, 14793, 21568, 30289, 41280, 54889, 71488, 91473, 115264, 143305, 176064, 214033, 257728, 307689, 364480, 428689, 500928, 581833, 672064, 772305, 883264, 1005673, 1140288, 1287889, 1449280, 1625289, 1816768, 2024593, 2249664, 2492905, 2755264

Offset: 0

Lamine Ngom, Jul 21 2021

The product of eight positive integers shifted by 2; i.e., m * (m+2) * (m+4) * ... * (m+14) = A346515(m) can always be expressed as the difference of two squares: x^2 - y^2.
This sequence gives the x-values for each product. The y-values are A152691(n+7).
More generally, for any k, we have n * (n+k) * (n+2*k) * ... * (n+7*k) = a(n,k) = x(n,k)^2 - y(n,k)^2, where
  x(n,k) = n^4 + 14*k*n^3 + 63*k^2*n^2 + 98*k^3*n + 28*k^4,
  y(n,k) = 4*k^3*(2*n + 7*k).
A239035(n) corresponds to a(n,k) in the case k = 1, with related y(n,k) = A346376(n).
This sequence is y(n,k) in the case k = 2, with related y(n,k) = A152691(n+7).

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Cf. A152691, A239035, A190577, A346515.

a(n) = sqrt(A346515(n) + A152691(n+7)^2).

G.f.: (448 - 727*x + 179*x^2 + 235*x^3 - 111*x^4)/(1 - x)^5. - Stefano Spezia, Jul 22 2021

A346515 a(n) = n(n+2)(n+4)(n+6)(n+8)(n+10)(n+12)*(n+14).

Original entry on oeis.org

0, 2027025, 10321920, 34459425, 92897280, 218243025, 464486400, 916620705, 1703116800, 3011753745, 5109350400, 8365982625, 13284311040, 20534684625, 30996725760, 45808142625, 66421555200, 94670161425, 132843110400, 183771489825, 250925875200, 338526428625, 451666575360

Offset: 0

Lamine Ngom, Jul 21 2021

a(n) can always be expressed as the difference of two squares: x^2 - y^2.
A346514(n) gives the x-values for each product. The y-values being A152691(n+7).
More generally, for any k, we have: n*(n+k)*(n+2*k)*...*(n+7*k) = a(n,k) = x(n,k)^2 - y(n,k)^2, where
  x(n,k) = n^4 + 14*k*n^3 + 63*k^2*n^2 + 98*k^3*n + 28*k^4,
  y(n,k) = 8*k^3*n + 28*k^4.
A239035(n) corresponds to a(n,k) in the case k = 1, with related y(n,k) = A346376(n).

Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).

Cf. A239035, A190577, A346514, A346376.

a[n_] := (n + 14)!!/(n - 2)!!; Array[a, 23, 0] (* Amiram Eldar, Jul 22 2021 *)

a(n) = A346514(n)^2 - A152691(n+7)^2.

A363436 Array read by ascending antidiagonals: A(n, k) = k*n^2, with k >= 0.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 4, 2, 0, 0, 9, 8, 3, 0, 0, 16, 18, 12, 4, 0, 0, 25, 32, 27, 16, 5, 0, 0, 36, 50, 48, 36, 20, 6, 0, 0, 49, 72, 75, 64, 45, 24, 7, 0, 0, 64, 98, 108, 100, 80, 54, 28, 8, 0, 0, 81, 128, 147, 144, 125, 96, 63, 32, 9, 0, 0, 100, 162, 192, 196, 180, 150, 112, 72, 36, 10, 0

Offset: 0

Stefano Spezia, Jul 08 2023

			The array begins:
  0,  0,  0,   0,   0,   0,   0, ...
  0,  1,  2,   3,   4,   5,   6, ...
  0,  4,  8,  12,  16,  20,  24, ...
  0,  9, 18,  27,  36,  45,  54, ...
  0, 16, 32,  48,  64,  80,  96, ...
  0, 25, 50,  75, 100, 125, 150, ...
  0, 36, 72, 108, 144, 180, 216, ...
  ...

Cf. A000290 (k = 1), A001105 (k = 2), A033428 (k = 3), A016742 (k = 4), A033429 (k = 5), A033581 (k = 6), A033582 (k = 7), A139098 (k = 8), A016766 (k = 9), A033583 (k = 10), A033584 (k = 11), A135453 (k = 12),  A152742 (k = 13), A144555 (k = 14), A064761 (k = 15), A016802 (k = 16), A244630 (k = 17), A195321 (k = 18), A244631 (k = 19), A195322 (k = 20), A064762 (k = 21), A195323 (k = 22), A244632 (k = 23), A195824 (k = 24), A016850 (k = 25), A244633 (k = 26), A244634 (k = 27), A064763 (k = 28), A244635 (k = 29), A244636 (k = 30).
Cf. A001477 (n = 1), A008586 (n = 2), A008591 (n = 3), A008598 (n = 4), A008607 (n = 5), A044102 (n = 6), A152691 (n = 8).
Cf. A000007 (n = 0 or k = 0), A000578 (main diagonal), A002415 (antidiagonal sums), A004247.

A[n_,k_]:=k n^2; Table[A[n-k,k],{n,0,11},{k,0,n}]//Flatten

O.g.f.: x*y*(1 + x)/((1 - x)^3*(1 - y)^2).
E.g.f.: x*y*(1 + x)*exp(x + y).
A(n, k) = n*A004247(n, k).

cp's OEIS Frontend

A174312 a(n) = 32*n.

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A017066 a(n) = (8*n)^2.

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A305548 a(n) = 27*n.

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A152692 a(n) = n*3^n - n*2^n - n*1^n.

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A158067 a(n) = 64*n^2 - 2*n.

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A327916 Triangle T(k, n) read by rows: Array A(k, n) = 2^k*(k + 1 + 2*n), k >= 0, n >= 0, read by antidiagonals upwards.

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A346514 a(n) = n^4 + 28*n^3 + 252*n^2 + 784*n + 448.

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A346515 a(n) = n*(n+2)*(n+4)*(n+6)*(n+8)*(n+10)*(n+12)*(n+14).

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A152692 a(n) = n3^n - n2^n - n*1^n.

A158067 a(n) = 64n^2 - 2n.

A327916 Triangle T(k, n) read by rows: Array A(k, n) = 2^k(k + 1 + 2n), k >= 0, n >= 0, read by antidiagonals upwards.

A346514 a(n) = n^4 + 28n^3 + 252n^2 + 784*n + 448.

A346515 a(n) = n(n+2)(n+4)(n+6)(n+8)(n+10)(n+12)*(n+14).