cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-6 of 6 results.

A183010 a(n) = 24*n - 1.

Original entry on oeis.org

-1, 23, 47, 71, 95, 119, 143, 167, 191, 215, 239, 263, 287, 311, 335, 359, 383, 407, 431, 455, 479, 503, 527, 551, 575, 599, 623, 647, 671, 695, 719, 743, 767, 791, 815, 839, 863, 887, 911, 935, 959, 983, 1007, 1031, 1055, 1079, 1103, 1127, 1151, 1175, 1199
Offset: 0

Views

Author

Omar E. Pol, Jan 21 2011

Keywords

Comments

a(n) is also the denominator of the finite algebraic formula for the number of partitions of n, if n >= 1. The formula is p(n) = Tr(n)/(24*n - 1), n >= 1. See theorem 1.1 of the Bruinier-Ono paper in the link. For the numerators see A183011.
It appears that a(n) is also the denominator of the coefficient of the third term in the n-th Bruinier-Ono "partition polynomial" H_n(x). See the Bruinier-Ono paper, chapter 5 "Examples". For the numerators see A183007. - Omar E. Pol, Jul 13 2011
Also exponents in the formula q^(-1) + q^23 + 2*q^47 + 3*q^71 + 5*q^95 + 7*q^119 + 11*q^143 + 15*q^167 + ... in which the coefficients are the partition numbers (see A000041, Example section). - Omar E. Pol, Feb 27 2013

Examples

			G.f. = -1 + 23*x + 47*x^2 + 71*x^3 + 95*x^4 + 119*x^5 + 143*x^6 + 167*x^7 + ...
		

Crossrefs

Cf. A000041, A000203, A008606, A134517 (subset of primes), A183009, A183011, A187206, A280097 (sum of divisors), A280098.
Cf. A008594.

Programs

Formula

a(n) = A008606(n) - 1.
a(1)=23, a(2)=47, a(n) = 2*a(n-1) - a(n-2). - Vincenzo Librandi, Jan 23 2011
a(n) = A183011(n)/A000041(n). - Omar E. Pol, Jul 14 2011
24 * A280098(n) = A000203(a(n)) if n>0. - Michael Somos, Dec 25 2016
E.g.f.: (24*x-1)*exp(x). - G. C. Greubel, Aug 14 2018
G.f.: (-1 + 25*x)/(1-x)^2. - Wolfdieter Lang, Dec 10 2021
a(n) = 2*A008594(n) - 1. - Leo Tavares, Jun 06 2023

A183011 (24n - 1)p(n): traces of partition class polynomials, with a(0) = -1.

Original entry on oeis.org

-1, 23, 94, 213, 475, 833, 1573, 2505, 4202, 6450, 10038, 14728, 22099, 31411, 45225, 63184, 88473, 120879, 165935, 222950, 300333, 398376, 528054, 691505, 905625, 1172842, 1517628, 1947470, 2494778, 3172675, 4029276, 5083606, 6403683, 8023113
Offset: 0

Views

Author

Omar E. Pol, Jan 21 2011

Keywords

Comments

a(n) is also Tr(n), the numerator of the finite algebraic formula for the number of partitions of n, if n >= 1. The formula is p(n) = Tr(n)/(24*n - 1), n >= 1. See theorem 1.1 of the Bruinier-Ono paper in the link. For the denominators see A183010.
a(n) is also the coefficient of the second term (the trace) in the n-th Bruinier-Ono "partition polynomial" H_n(x), if n >= 1. See the Bruinier-Ono paper, theorem 1.1 and chapter 5 "Examples". For the coefficients of the 4th terms see A187218. - Omar E. Pol, Jul 10 2011
In the Bruinier-Ono-Sutherland paper (Jan 23 2013) partition polynomials are called "partition class polynomials". See also Sutherland's table of Hpart_n(x) in link section. - Omar E. Pol, Feb 20 2013

Examples

			1. For n = 6, the number of partitions of 6 is 11, so a(6) = (24*6 - 1)*11 = 143*11 = 1573.
2. For n = 1, in the Bruinier-Ono paper, chapter 5, the first "partition polynomial" is H_1(x) = x^3 - 23*x^2 + (3592/23)*x - 419. The coefficient of the second term (the trace) is 23, so a(1) = 23.
G.f. = -1 + 23*x + 94*x^2 + 213*x^3 + 475*x^4 + 833*x^5 + 1573*x^6 + 2505*x^7 + ...
G.f. = -q^-1 + 23*q^23 + 94*q^47 + 213*q^71 + 475*q^95 + 833*q^119 + 1573*q^143 + ...
		

Crossrefs

Positive terms are the partial sums of A183012, also the column 24 of A182729.

Programs

  • Mathematica
    a[ n_] := (24 n - 1) SeriesCoefficient[ 1 / QPochhammer[ x], {x, 0, n}]; (* Michael Somos, Jun 26 2017 *)
  • PARI
    {a(n) = if( n<0, 0, (24*n - 1) * numbpart(n))}; /* Michael Somos, Aug 28 2013 */

Formula

a(n) = A183010(n)*A000041(n).
a(n) = 24*A066186(n) - A000041(n) = A183009(n) - A000041(n) = (A008606(n)-1)*A000041(n).
a(n) = 12M_2(n) - p(n) = 24spt(n) + 12N_2(n) - p(n) = 12*A220909(n) - A000041(n) = 24*A092269(n) + 12*A220908(n) - A000041(n), n >= 1. - Omar E. Pol, Feb 17 2013
G.f.: Sum_{k >= 0} a(k) * q^(24*k - 1) = q * d/dq (1/q * Product_{k > 0} 1 / (1 - q^(24*k))). - Michael Somos, Aug 28 2013

A182728 Array T(n,k) = n*k*A000041(n) read by antidiagonals, n,k >= 1.

Original entry on oeis.org

1, 4, 2, 9, 8, 3, 20, 18, 12, 4, 35, 40, 27, 16, 5, 66, 70, 60, 36, 20, 6, 105, 132, 105, 80, 45, 24, 7, 176, 210, 198, 140, 100, 54, 28, 8, 270, 352, 315, 264, 175, 120, 63, 32, 9, 420, 540, 528, 420, 330, 210, 140, 72, 36, 10, 616, 840, 810, 704, 525, 396, 245, 160, 81, 40, 11
Offset: 1

Views

Author

Omar E. Pol, Jan 22 2011

Keywords

Examples

			Array begins:
    1,   2,   3,   4,   5,   6,   7, ...
    4,   8,  12,  16,  20,  24,  28, ...
    9,  18,  27,  36,  45,  54,  63, ...
   20,  40,  60,  80, 100, 120, 140, ...
   35,  70, 105, 140, 175, 210, 245, ...
   66, 132, 198, 264, 330, 396, 462, ...
  105, 210, 315, 420, 525, 630, 735, ...
		

Crossrefs

Column 1 gives A066186. Column 24 gives A183009.

Programs

  • Maple
    A182728 := proc(n,k) n*k*combinat[numbpart](n) ; end proc:
    seq(seq( A182728(d+1-k, k), k=1..d), d=1..10) ; # R. J. Mathar, Feb 01 2011

A182729 Square array T(n,k) = (n*k-1)*A000041(n) read by antidiagonals upwards.

Original entry on oeis.org

0, 2, 1, 6, 6, 2, 15, 15, 10, 3, 28, 35, 24, 14, 4, 55, 63, 55, 33, 18, 5, 90, 121, 98, 75, 42, 22, 6, 154, 195, 187, 133, 95, 51, 26, 7, 240, 330, 300, 253, 168, 115, 60, 30, 8, 378, 510, 506, 405, 319, 203, 135, 69, 34, 9
Offset: 1

Views

Author

Omar E. Pol, Jan 22 2011

Keywords

Examples

			Square array T(n,k) begins:
   0,   1,   2,   3,   4,   5, ...
   2,   6,  10,  14,  18,  22, ...
   6,  15,  24,  33,  42,  51, ...
  15,  35,  55,  75,  95, 115, ...
  28,  63,  98, 133, 168, 203, ...
  55, 121, 187, 253, 319, 385, ...
		

Crossrefs

Programs

  • Maple
    T:= (n,k)-> (n*k-1)*combinat[numbpart](n):
    seq (seq (T(d-k, k), k=1..d-1), d=2..11);
  • Mathematica
    Table[With[{n = m - k + 1}, (n k - 1) PartitionsP[n]], {m, 10}, {k, m}] // Flatten (* Michael De Vlieger, Nov 02 2017 *)

Formula

T(n,1) = A182724(n).
T(n,24) = A183011(n).

A187206 a(n) = 6*(24*n - 1).

Original entry on oeis.org

138, 282, 426, 570, 714, 858, 1002, 1146, 1290, 1434, 1578, 1722, 1866, 2010, 2154, 2298, 2442, 2586, 2730, 2874, 3018, 3162, 3306, 3450, 3594, 3738, 3882, 4026, 4170, 4314, 4458, 4602, 4746, 4890, 5034, 5178, 5322, 5466, 5610, 5754, 5898, 6042, 6186, 6330, 6474, 6618
Offset: 1

Views

Author

Omar E. Pol, Jul 09 2011

Keywords

Comments

The expression 6*(24*n - 1) is mentioned in the Bruinier-Ono paper (see theorem 1.1 and chapter 5).

Crossrefs

Programs

Formula

a(n) = 6*A183010(n).
From Elmo R. Oliveira, Apr 03 2025: (Start)
G.f.: 6*x*(x + 23)/(1 - x)^2.
E.g.f.: 6*(exp(x)*(24*x - 1) + 1).
a(n) = 2*a(n-1) - a(n-2) for n > 2. (End)

A183006 a(n) = 24*A138879(n).

Original entry on oeis.org

24, 72, 120, 264, 360, 744, 936, 1704, 2256, 3600, 4704, 7392
Offset: 1

Views

Author

Omar E. Pol, Jan 23 2011

Keywords

Comments

a(n) is also the sum of all "sectors" or "half-periods" of the last section of the set of partitions of n (Cf. A135010).

Crossrefs

Partial sums give A183009.
Showing 1-6 of 6 results.