A014106 -id:A014106 - cp's OEIS frontend

A139273 a(n) = n(8n - 3).

0, 5, 26, 63, 116, 185, 270, 371, 488, 621, 770, 935, 1116, 1313, 1526, 1755, 2000, 2261, 2538, 2831, 3140, 3465, 3806, 4163, 4536, 4925, 5330, 5751, 6188, 6641, 7110, 7595, 8096, 8613, 9146, 9695, 10260, 10841, 11438, 12051, 12680

Offset: 0

Omar E. Pol, Apr 26 2008

Sequence found by reading the line from 0, in the direction 0, 5, ..., in the square spiral whose vertices are the triangular numbers A000217. Opposite numbers to the members of A139277 in the same spiral.
Also, sequence of numbers of the form d*A000217(n-1) + 5*n with generating functions x*(5+(d-5)*x)/(1-x)^3; the inverse binomial transform is 0,5,d,0,0,.. (0 continued). See Crossrefs. - Bruno Berselli, Feb 11 2011
Even decagonal numbers divided by 2. - Omar E. Pol, Aug 19 2011

G. C. Greubel, Table of n, a(n) for n = 0..5000
Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A000217, A014634, A014635, A033585, A033586, A033587, A035008, A051870, A069129, A085250, A072279, A139272, A139274, A139275, A139276, A139278, A139279, A139280, A139281, A139282.

Cf. numbers of the form n*(d*n+10-d)/2: A008587, A056000, A028347, A140090, A014106, A028895, A045944, A186029, A007742, A022267, A033429, A022268, A049452, A186030, A135703, A152734.

[ n*(8*n-3) : n in [0..40] ];  // Bruno Berselli, Feb 11 2011

Table[n (8 n - 3), {n, 0, 40}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 5, 26}, 40] (* Harvey P. Dale, Feb 02 2012 *)

a(n)=n*(8*n-3) \\ Charles R Greathouse IV, Sep 24 2015

a(n) = 8*n^2 - 3*n.
Sequences of the form a(n) = 8*n^2 + c*n have generating functions x{c+8+(8-c)x} / (1-x)^3 and recurrence a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). The inverse binomial transform is 0, c+8, 16, 0, 0, ... (0 continued). This applies to A139271-A139278, positive or negative c. - R. J. Mathar, May 12 2008
a(n) = 16*n + a(n-1) - 11 for n>0, a(0)=0. - Vincenzo Librandi, Aug 03 2010
From Bruno Berselli, Feb 11 2011: (Start)
G.f.: x*(5 + 11*x)/(1 - x)^3.
a(n) = 4*A000217(n) + A051866(n). (End)
a(n) = A028994(n)/2. - Omar E. Pol, Aug 19 2011
a(0)=0, a(1)=5, a(2)=26; for n>2, a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Harvey P. Dale, Feb 02 2012
E.g.f.: (8*x^2 + 5*x)*exp(x). - G. C. Greubel, Jul 18 2017
Sum_{n>=1} 1/a(n) = 4*log(2)/3 - (sqrt(2)-1)*Pi/6 - sqrt(2)*arccoth(sqrt(2))/3. - Amiram Eldar, Jul 03 2020

A059255 Both sum of n+1 consecutive squares and sum of the immediately following n consecutive squares.

Original entry on oeis.org

0, 25, 365, 2030, 7230, 19855, 45955, 94220, 176460, 308085, 508585, 802010, 1217450, 1789515, 2558815, 3572440, 4884440, 6556305, 8657445, 11265670, 14467670, 18359495, 23047035, 28646500, 35284900, 43100525, 52243425, 62875890, 75172930, 89322755, 105527255, 124002480

Offset: 0

Henry Bottomley, Jan 23 2001

The analog for sums of integers is A059270, and the analog for sums of triangular numbers is A222716. - Jonathan Sondow, Mar 07 2013

In 1879, Dostor gave formulas for all solutions -- see the Dickson link. - Jonathan Sondow, Jun 21 2014

			a(3) = 2030 = 21^2 + 22^2 + 23^2 + 24^2 = 25^2 + 26^2 + 27^2.

Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966. See Table 68 at p. 152.

Vincenzo Librandi, Table of n, a(n) for n = 0..1000
M. Boardman, Proof Without Words: Pythagorean Runs, Math. Mag., 73 (2000), 59.
L. E. Dickson, History of the Theory of Numbers, II, p. 320.
Georges Dostor, Question sur les nombres, Archiv der Mathematik und Physik, 64 (1879), 350-352.
Greg Frederickson, Casting Light on Cube Dissections, Math. Mag., 82 (2009), 323-331.
Vladimir Gurvich and Mariya Naumova, On pairs of triangular numbers whose product is a perfect square and pairs of intervals of successive integers with equal sums of squares, arXiv:2508.06598 [math.NT], 2025. See p. 3.
Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

The n+1 consecutive squares start with the square of A014105, while the n consecutive squares start with the square of A001844.
Cf. also A059270, A222716.
Cf. A234319 for nonexistence of analogs for sums of n-th powers, n > 2. - Jonathan Sondow, Apr 23 2014

[n*(n+1)*(2*n+1)*(12*n^2+12*n+1)/6 : n in [0..50]]; // Wesley Ivan Hurt, Jun 21 2014

A059255:=n->n*(n+1)*(2*n+1)*(12*n^2+12*n+1)/6; seq(A059255(n), n=0..50); # Wesley Ivan Hurt, Jun 21 2014

Table[1/6(-1+n)(-n+14n^2-36n^3+24n^4),{n,40}] (* or *) LinearRecurrence[ {6,-15,20,-15,6,-1},{0,25,365,2030,7230,19855},40] (* Harvey P. Dale, May 09 2011 *)

a(n)=n*(n+1)*(2*n+1)*(12*n^2+12*n+1)/6 \\ Charles R Greathouse IV, Jul 27 2021

a(n) = n*(n + 1)*(2n + 1)*(12n^2 + 12n + 1)/6.
a(n) = 4*n^5 + 10*n^4 + (25/3)*n^3 + (5/2)*n^2 + (1/6)*n. [Corrected by Ignacio Larrosa Cañestro, Nov 15 2021]
a(n) = A000330(A046092(n)) - A000330(A014107(n + 1)).
a(n) = A000330(A014106(n)) - A000330(A046092(n)).
From Harvey P. Dale, May 09 2011: (Start)
G.f.: (5x(1+x)(5+x(38+5x)))/(x-1)^6.
a(0)=0, a(1)=25, a(2)=365, a(3)=2030, a(4)=7230, a(5)=19855, a(n) = 6a(n-1)-15a(n-2)+20a(n-3)-15a(n-4)+6a(n-5)-a(n-6). (End)
a(n) = (4*T(n)-n)^2+(4*T(n)-n+1)^2+...+(4*T(n))^2 = (4*T(n)+1)^2+(4*T(n)+2)^2+...+(4*T(n)+n)^2, where T = A000217. See Boardman (2000). - Jonathan Sondow, Mar 07 2013
a(0)=0, a(n) = 25 + 340*C(n-1,1) + 1325*C(n-1,2) + 2210*C(n-1,3) + 1680*C(n-1,4) + 480*C(n-1,5) for n >= 1, where C(a,b) are binomial coefficients. - Kieren MacMillan, Sep 16 2014
E.g.f.: exp(x)*x*(150 + 945*x + 1010*x^2 + 300*x^3 + 24*x^4)/6. - Stefano Spezia, Aug 05 2024

A135703 a(n) = n(7n-2).

Original entry on oeis.org

0, 5, 24, 57, 104, 165, 240, 329, 432, 549, 680, 825, 984, 1157, 1344, 1545, 1760, 1989, 2232, 2489, 2760, 3045, 3344, 3657, 3984, 4325, 4680, 5049, 5432, 5829, 6240, 6665, 7104, 7557, 8024, 8505, 9000, 9509, 10032, 10569, 11120, 11685, 12264, 12857, 13464

Offset: 0

N. J. A. Sloane, Mar 04 2008

G. C. Greubel, Table of n, a(n) for n = 0..2500
L. Hogben, Choice and Chance by Cardpack and Chessboard, Vol. 1, Max Parrish and Co, London, 1950, p. 36.
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. index to numbers of the form n*(d*n+10-d)/2 in A014106.

Cf. A185019.

List([0..50], n-> n*(7*n-2)); # G. C. Greubel, Jul 04 2019

[n*(7*n-2): n in [0..50]]; // G. C. Greubel, Jul 04 2019

Array[ #*(7*# - 2) &, 50, 0] (* Zerinvary Lajos, Jul 10 2009 *)

a(n)=n*(7*n-2) \\ Charles R Greathouse IV, Oct 07 2015

[n*(7*n-2) for n in (0..50)] # G. C. Greubel, Jul 04 2019

a(n) = 5*n + 14*binomial(n,2).
From R. J. Mathar, Apr 21 2008: (Start)
O.g.f. x*(5+9*x)/(1-x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). (End)
a(n) = a(n-1) + 14*n - 9 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
a(n) = 4*A000217(n) + A051624(n). - Bruno Berselli, Feb 11 2011
E.g.f.: x*(5 + 7*x)*exp(x). - G. C. Greubel, Oct 29 2016

A211377 T(n,k) = ((k + n)^2 - 4k + 3 + (-1)^k - (k + n - 2)(-1)^(k + n))/2; n, k > 0, read by antidiagonals.

Original entry on oeis.org

1, 3, 4, 2, 5, 6, 8, 9, 12, 13, 7, 10, 11, 14, 15, 17, 18, 21, 22, 25, 26, 16, 19, 20, 23, 24, 27, 28, 30, 31, 34, 35, 38, 39, 42, 43, 29, 32, 33, 36, 37, 40, 41, 44, 45, 47, 48, 51, 52, 55, 56, 59, 60, 63, 64, 46, 49, 50, 53, 54, 57, 58, 61, 62, 65, 66, 68

Offset: 1

Boris Putievskiy, Feb 07 2013

Permutation of the natural numbers.
a(n) is a pairing function: a function that reversibly maps Z^{+} x Z^{+} onto Z^{+}, where Z^{+} is the set of integer positive numbers.
Enumeration table T(n,k). The order of the list:
T(1,1)=1;
T(1,3), T(1,2), T(2,1), T(2,2), T(3,1);
...
T(1,n), T(1,n-1), T(2,n-2), T(2,n-1), T(3,n-2), T(3,n-3)...T(n,1);
...
Descent by snake along two adjacent antidiagonal - step to the west, step to the southwest, step to the east, step to the southwest and so on.  The length of each step is 1.
Table contains:
row 1 is alternation of elements A130883 and A033816,
row 2 accommodates elements A100037 in odd places;
column 1 is alternation of elements A000384 and A091823,
column 2 is alternation of elements A071355 and A014106,
column 3 accommodates elements A130861 in even places;
main diagonal accommodates elements A188135 in odd places,
diagonal 1, located above the main diagonal, is alternation of elements A033567 and A033566,
diagonal 2, located above the main diagonal, is alternation of elements A139271 and A033585.

			The start of the sequence as a table:
   1,  3,  2,   8,   7,  17,  16,  30,  29,  47,  46, ...
   4,  5,  9,  10,  18,  19,  31,  32,  48,  49,  69, ...
   6, 12, 11,  21,  20,  34,  33,  51,  50,  72,  71, ...
  13, 14, 22,  23,  35,  36,  52,  53,  73,  74,  98, ...
  15, 25, 24,  38,  37,  55,  54,  76,  75, 101, 100, ...
  26, 27, 39,  40,  56,  57,  77,  78, 102, 103, 131, ...
  28, 42, 41,  59,  58,  80,  79, 105, 104, 134, 133, ...
  43, 44, 60,  61,  81,  82, 106, 107, 135, 136, 168, ...
  45, 63, 62,  84,  83, 109, 108, 138, 137, 171, 170, ...
  64, 65, 85,  86, 110, 111, 139, 140, 172, 173, 209, ...
  66, 88, 87, 113, 112, 142, 141, 175, 174, 212, 211, ...
  ...
The start of the sequence as triangle array read by rows:
   1;
   3,  4;
   2,  5,  6;
   8,  9, 12, 13;
   7, 10, 11, 14, 15;
  17, 18, 21, 22, 25, 26;
  16, 19, 20, 23, 24, 27, 28;
  30, 31, 34, 35, 38, 39, 42, 43;
  29, 32, 33, 36, 37, 40, 41, 44, 45;
  47, 48, 51, 52, 55, 56, 59, 60, 63, 64;
  46, 49, 50, 53, 54, 57, 58, 61, 62, 65, 66;
  ...
The start of the sequence as an array read by rows, the length of row r is 4*r-3.
First 2*r-2 numbers are from row number 2*r-2 of the triangular array above.
Last  2*r-1 numbers are from row number 2*r-1 of the triangular array above.
   1;
   3,  4,  2,  5,  6;
   8,  9, 12, 13,  7, 10, 11, 14, 15;
  17, 18, 21, 22, 25, 26, 16, 19, 20, 23, 24, 27, 28;
  30, 31, 34, 35, 38, 39, 42, 43, 29, 32, 33, 36, 37, 40, 41, 44, 45;
  47, 48, 51, 52, 55, 56, 59, 60, 63, 64, 46, 49, 50, 53, 54, 57, 58, 61, 62, 65, 66;
  ...
Row number r contains permutation 4*r-3 numbers from 2*r*r-5*r+4 to 2*r*r-r:
2*r*r-5*r+5, 2*r*r-5*r+6,...2*r*r-r-4, 2*r*r-r-1, 2*r*r-r.

Boris Putievskiy, Rows n = 1..140 of triangle, flattened
Boris Putievskiy, Transformations [of] Integer Sequences And Pairing Functions arXiv:1212.2732 [math.CO], 2012.
Eric W. Weisstein, MathWorld: Pairing functions
Index entries for sequences that are permutations of the natural numbers

Cf. A000384, A014106, A033566, A033567, A033585, A033816, A071355, A091823, A100037, A130861, A130883, A139271, A188135.

T[n_, k_] := ((k+n)^2 - 4k + 3 + (-1)^k - (k+n-2)(-1)^(k+n))/2;
Table[T[n-k+1, k], {n, 1, 12}, {k, n, 1, -1}] // Flatten (* Jean-François Alcover, Nov 29 2018 *)

t=int((math.sqrt(8*n-7) - 1)/ 2)
i=n-t*(t+1)/2
j=(t*t+3*t+4)/2-n
result=((t+2)**2-4*j+3+(-1)**j-t*(-1)**(t+2))/2

As a table:
T(n,k) = ((k + n)^2 - 4*k + 3 + (-1)^k - (k + n - 2)*(-1)^(k + n))/2.
As a linear sequence:
a(n) = ((t + 2)^2 - 4*j + 3 + (-1)^j - t*(-1)^t)/2, where j = (t*t + 3*t + 4)/2 - n and t = int((sqrt(8*n - 7) - 1)/ 2).

A139579 a(n) = 2n^2 + 15n.

Original entry on oeis.org

0, 17, 38, 63, 92, 125, 162, 203, 248, 297, 350, 407, 468, 533, 602, 675, 752, 833, 918, 1007, 1100, 1197, 1298, 1403, 1512, 1625, 1742, 1863, 1988, 2117, 2250, 2387, 2528, 2673, 2822, 2975, 3132, 3293, 3458, 3627, 3800, 3977, 4158, 4343, 4532, 4725, 4922, 5123, 5328, 5537

Offset: 0

Omar E. Pol, May 19 2008

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

Cf. A014105, A014106, A033537, A130861, A139576, A139577, A139578, A139580, A139581.

LinearRecurrence[{3,-3,1},{0,17,38},50] (* Stefano Spezia, Oct 21 2023 *)

a(n)=2*n^2+15*n \\ Charles R Greathouse IV, Jun 17 2017

a(n) = a(n-1) + 4*n + 13; a(0) = 0. - Vincenzo Librandi, Nov 24 2010
From Stefano Spezia, Oct 21 2023: (Start)
O.g.f.: x*(17 - 13*x)/(1 - x)^3.
E.g.f.: exp(x)*x*(17 + 2*x). (End)
From Amiram Eldar, Nov 10 2023: (Start)
Sum_{n>=1} 1/a(n) = 182144/675675 - 2*log(2)/15.
Sum_{n>=1} (-1)^(n+1)/a(n) = log(2)/15 - Pi/30 + 67952/675675. (End)

A181890 a(n) = 8n^2 + 14n + 5.

Original entry on oeis.org

5, 27, 65, 119, 189, 275, 377, 495, 629, 779, 945, 1127, 1325, 1539, 1769, 2015, 2277, 2555, 2849, 3159, 3485, 3827, 4185, 4559, 4949, 5355, 5777, 6215, 6669, 7139, 7625, 8127, 8645, 9179, 9729, 10295, 10877, 11475, 12089, 12719, 13365, 14027, 14705, 15399, 16109, 16835, 17577

Offset: 0

Paul Curtz, Feb 01 2011

A160050(4*n+1) = A033954(n); A160050(4*n+2) = A001107(n); the third quadrisection is a(n).
First 16 terms of clockwise spiral for odd numbers are as follows:
.
  13--15--17--19
   |           |
  11   1---3  21
   |       |   |
   9---7---5  23
               |
  31--29--27--25
.
a(n) comes from the third vertical.
Sequence found by reading the line from 5, in the direction 5, 27, in the square spiral whose vertices are the triangular numbers A000217. - Omar E. Pol, Dec 25 2011

Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A000217, A001107, A014106, A014635, A033954, A064038, A160050.

[8*n^2+14*n+5: n in [0..700]]; // Vincenzo Librandi, Feb 01 2011

Table[(2n+1)(4n+5),{n,0,40}]  (* Harvey P. Dale, Feb 06 2011 *)
CoefficientList[Series[(5 + 12 x - x^2)/(1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, May 23 2014 *)

a(n)=8*n^2+14*n+5 \\ Charles R Greathouse IV, Dec 21 2011

a(n) = A160050(4*n+3).
a(n) = (2*n+1)*(4*n+5).
a(n) = a(n-1) + 16*n + 6.
a(n) = 2*a(n-1) - a(n-2) + 16.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: (5 + 12*x - x^2)/(1 - x)^3. - Arkadiusz Wesolowski, Dec 25 2011
a(n) = A014635(n+1) - 1. - Omar E. Pol, Dec 25 2011
From Vaclav Kotesovec, Aug 18 2018: (Start)
Sum_{n>=0} 1/a(n) = 2/3 - Pi/12 - log(2)/6 = 0.289342748774193011891907697817...
Sum_{n>=0} (-1)^n / a(n) = (1 + sqrt(2))*Pi/12 - 2/3 - sqrt(2)*log(tan(Pi/8))/6 = 0.173114712692423461587883724528539... (End)
a(n) = A014106(2*n+1). - Rick L. Shepherd, Aug 06 2019
E.g.f.: (5 + 22*x + 8*x^2)*exp(x). - Elmo R. Oliveira, Oct 19 2024

A286108 Square array read by antidiagonals: A(n,k) = T(2*(n AND k), n XOR k), where T(n,k) is sequence A001477 considered as a two-dimensional table, AND is bitwise-and (A004198) and XOR is bitwise-xor (A003987).

Original entry on oeis.org

0, 1, 1, 3, 5, 3, 6, 6, 6, 6, 10, 12, 14, 12, 10, 15, 15, 19, 19, 15, 15, 21, 23, 21, 27, 21, 23, 21, 28, 28, 28, 28, 28, 28, 28, 28, 36, 38, 40, 38, 44, 38, 40, 38, 36, 45, 45, 49, 49, 53, 53, 49, 49, 45, 45, 55, 57, 55, 61, 63, 65, 63, 61, 55, 57, 55, 66, 66, 66, 66, 74, 74, 74, 74, 66, 66, 66, 66, 78, 80, 82, 80, 78, 88, 90, 88, 78, 80, 82, 80, 78

Offset: 0

Antti Karttunen, May 03 2017

The array is read by descending antidiagonals as A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), ...

			The top left 0 .. 12 x 0 .. 12 corner of the array:
   0,  1,   3,   6,  10,  15,  21,  28,  36,  45,  55,  66,  78
   1,  5,   6,  12,  15,  23,  28,  38,  45,  57,  66,  80,  91
   3,  6,  14,  19,  21,  28,  40,  49,  55,  66,  82,  95, 105
   6, 12,  19,  27,  28,  38,  49,  61,  66,  80,  95, 111, 120
  10, 15,  21,  28,  44,  53,  63,  74,  78,  91, 105, 120, 144
  15, 23,  28,  38,  53,  65,  74,  88,  91, 107, 120, 138, 161
  21, 28,  40,  49,  63,  74,  90, 103, 105, 120, 140, 157, 179
  28, 38,  49,  61,  74,  88, 103, 119, 120, 138, 157, 177, 198
  36, 45,  55,  66,  78,  91, 105, 120, 152, 169, 187, 206, 226
  45, 57,  66,  80,  91, 107, 120, 138, 169, 189, 206, 228, 247
  55, 66,  82,  95, 105, 120, 140, 157, 187, 206, 230, 251, 269
  66, 80,  95, 111, 120, 138, 157, 177, 206, 228, 251, 275, 292
  78, 91, 105, 120, 144, 161, 179, 198, 226, 247, 269, 292, 324

Antti Karttunen, Table of n, a(n) for n = 0..10584; the first 145 antidiagonals of array
Eric Weisstein's World of Mathematics, Pairing Function

Cf. A000217 (row 0 & column 0), A014106 (main diagonal).
Cf. A003056, A003987, A004198.
Cf. also arrays A286098, A286109, A286145, A286147, A286150, A286151.

T[a_, b_]:=((a + b)^2 + 3a + b)/2; A[n_, k_]:=T[2*BitAnd[n, k], BitXor[n, k]]; Table[A[k, n - k ], {n, 0, 20}, {k, 0, n}] // Flatten (* Indranil Ghosh, May 20 2017 *)

def T(a, b): return ((a + b)**2 + 3*a + b)//2
def A(n, k): return T(2*(n&k), n^k)
for n in range(21): print([A(k, n - k) for k in range(n + 1)]) # Indranil Ghosh, May 20 2017

(define (A286108 n) (A286108bi (A002262 n) (A025581 n)))
(define (A286108bi row col) (let ((a (* 2 (A004198bi row col))) (b (A003987bi row col))) (/ (+ (expt (+ a b) 2) (* 3 a) b) 2))) ;; Here A003987bi and A004198bi implement bitwise-xor (A003987) and bitwise-and (A004198).

A(n,k) = T(2*A004198(n,k), A003987(n,k)), where T(n,k) is sequence A001477 considered as a two-dimensional table, that is, as a pairing function from [0, 1, 2, 3, ...] x [0, 1, 2, 3, ...] to [0, 1, 2, 3, ...].

A139576 a(n) = n(2n + 9).

Original entry on oeis.org

0, 11, 26, 45, 68, 95, 126, 161, 200, 243, 290, 341, 396, 455, 518, 585, 656, 731, 810, 893, 980, 1071, 1166, 1265, 1368, 1475, 1586, 1701, 1820, 1943, 2070, 2201, 2336, 2475, 2618, 2765, 2916, 3071, 3230, 3393, 3560, 3731, 3906

Offset: 0

Omar E. Pol, May 19 2008

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A014105, A014106, A033537, A130861, A139577, A139578, A139579, A139580, A139581.

Cf. A277979.

s=0;lst={s};Do[s+=n++ +11;AppendTo[lst, s], {n, 0, 7!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)
Table[Sum[(2*i + n - 1), {i, 4, n}], {n, 3, 45}] (* Zerinvary Lajos, Jul 11 2009 *)
Table[n(2n+9),{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{0,11,26},50] (* Harvey P. Dale, Dec 18 2018 *)

a(n)=n*(2*n+9) \\ Charles R Greathouse IV, Jun 17 2017

a(n) = 2*n^2 + 9*n.
a(n) = a(n-1) + 4*n + 7 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
From Elmo R. Oliveira, Nov 29 2024: (Start)
G.f.: x*(11 - 7*x)/(1-x)^3.
E.g.f.: exp(x)*x*(11 + 2*x).
a(n) = A277979(n)/2.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)

A139577 a(n) = n(2n + 11).

Original entry on oeis.org

0, 13, 30, 51, 76, 105, 138, 175, 216, 261, 310, 363, 420, 481, 546, 615, 688, 765, 846, 931, 1020, 1113, 1210, 1311, 1416, 1525, 1638, 1755, 1876, 2001, 2130, 2263, 2400, 2541, 2686, 2835, 2988, 3145, 3306, 3471, 3640, 3813, 3990

Offset: 0

Omar E. Pol, May 19 2008

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A014105, A014106, A033537, A130861, A139576, A139578, A139579, A139580, A139581.

s=0;lst={s};Do[s+=n++ +13;AppendTo[lst, s], {n, 0, 7!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)
Table[n(2n+11),{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{0,13,30},50] (* Harvey P. Dale, Mar 17 2019 *)

a(n)=n*(2*n+11) \\ Charles R Greathouse IV, Jun 17 2017

a(n) = 2*n^2 + 11*n.
a(n) = a(n-1) + 4*n + 9 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
From Elmo R. Oliveira, Nov 29 2024: (Start)
G.f.: x*(13 - 9*x)/(1-x)^3.
E.g.f.: exp(x)*x*(13 + 2*x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)

A139578 a(n) = n(2n + 13).

Original entry on oeis.org

0, 15, 34, 57, 84, 115, 150, 189, 232, 279, 330, 385, 444, 507, 574, 645, 720, 799, 882, 969, 1060, 1155, 1254, 1357, 1464, 1575, 1690, 1809, 1932, 2059, 2190, 2325, 2464, 2607, 2754, 2905, 3060, 3219, 3382, 3549, 3720, 3895, 4074, 4257, 4444, 4635, 4830, 5029

Offset: 0

Omar E. Pol, May 19 2008

Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Cf. A014105, A014106, A033537, A130861, A139576, A139577, A139579, A139580, A139581.

s=0;lst={s};Do[s+=n++ +15;AppendTo[lst, s], {n, 0, 7!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)
Table[n(2n+13),{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{0,15,34},50] (* Harvey P. Dale, Nov 22 2014 *)

a(n)=n*(2*n+13) \\ Charles R Greathouse IV, Oct 07 2015

a(n) = 2*n^2 + 13*n.
a(n) = a(n-1) + 4*n + 11 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
From Elmo R. Oliveira, Nov 29 2024: (Start)
G.f.: x*(15 - 11*x)/(1 - x)^3.
E.g.f.: exp(x)*x*(15 + 2*x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)

cp's OEIS Frontend

A139273 a(n) = n*(8*n - 3).

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A059255 Both sum of n+1 consecutive squares and sum of the immediately following n consecutive squares.

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A135703 a(n) = n*(7*n-2).

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A211377 T(n,k) = ((k + n)^2 - 4*k + 3 + (-1)^k - (k + n - 2)*(-1)^(k + n))/2; n, k > 0, read by antidiagonals.

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A139579 a(n) = 2*n^2 + 15*n.

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A181890 a(n) = 8*n^2 + 14*n + 5.

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A286108 Square array read by antidiagonals: A(n,k) = T(2*(n AND k), n XOR k), where T(n,k) is sequence A001477 considered as a two-dimensional table, AND is bitwise-and (A004198) and XOR is bitwise-xor (A003987).

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A139273 a(n) = n(8n - 3).

A135703 a(n) = n(7n-2).

A211377 T(n,k) = ((k + n)^2 - 4k + 3 + (-1)^k - (k + n - 2)(-1)^(k + n))/2; n, k > 0, read by antidiagonals.

A139579 a(n) = 2n^2 + 15n.

A181890 a(n) = 8n^2 + 14n + 5.

A139576 a(n) = n(2n + 9).

A139577 a(n) = n(2n + 11).

A139578 a(n) = n(2n + 13).