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 1-3 of 3 results.

A220515 Numbers n such that A183054(n) is not equal to A188569(n).

Original entry on oeis.org

24, 47, 49, 74, 96, 99, 116, 124, 145, 149, 162, 174, 194, 199, 224, 237, 243, 249, 274, 277, 292, 299, 324, 331, 341, 346, 349, 358, 374, 390, 399, 424, 439, 449, 474, 479, 488, 499, 500, 507, 524, 537, 549, 566, 574, 586, 599, 600, 624, 635
Offset: 1

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Author

Omar E. Pol, Feb 27 2013

Keywords

Comments

For an algorithm to compute the partition class polynomial Hpart_n(x) see the Bruinier-Ono-Sutherland paper, 3.3. Algorithm 3, p. 15-19. For more information see A222031.

Examples

			First three terms are 24, 47, 49 because first 50 terms of A183054 coincide with first 50 terms of A188569 except for the indices 24, 47, 49 as shown below:
(A183054(24) = 3) < (A188569(24) = 21).
(A183054(47) = 3) < (A188569(47) = 27).
(A183054(49) = 5) < (A188569(49) = 35).
Observation:
A183054(24) = A188569(24)/7 = 3.
A183054(47) = A188569(47)/9 = 3.
A183054(49) = A188569(49)/7 = 5.
		

Crossrefs

Extensions

a(4)-a(50) from Giovanni Resta, Mar 04 2013

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

A188569 Degree of the n-th partition class polynomial Hpart_n(x).

Original entry on oeis.org

3, 5, 7, 8, 10, 10, 11, 13, 14, 15, 13, 14, 19, 18, 19, 17, 16, 21, 20, 25, 21, 18, 26, 21, 25, 22, 23, 30, 24, 31, 21, 22, 32, 30, 33, 21, 29, 31, 28, 36, 27, 30, 35, 36, 34, 23, 27, 41, 35, 38, 35, 26, 40, 36, 45, 34, 25, 44, 34, 39, 32, 37, 49, 38, 51, 33
Offset: 1

Views

Author

Omar E. Pol, Feb 21 2013

Keywords

Comments

a(n) is the degree of the n-th partition class polynomial whose trace is the numerator of the finite algebraic formula for the number of partitions of n. The formula for the partition function is p(n) = Tr(n)/(24n - 1). See theorem 1.1 in the Bruinier-Ono paper. The traces are in A183011. See also Sutherland's table of Hpart_n(x) in the Links section.
First differs from A183054 at a(24). It appears that this coincides with A183054 in a large number of terms.

Examples

			In the Bruinier-Ono paper, chapter 5 "Examples", the first "partition polynomial" is H_1(x) = x^3 - 23*x^2 + (3592/23)*x - 419, which has degree 3, so a(1) = 3.
		

Crossrefs

Extensions

This sequence arises from the original definition of A183054 (Jul 14 2011) which was changed.
Showing 1-3 of 3 results.