A220907 -id:A220907 - cp's OEIS frontend

A092269 Spt function: total number of smallest parts (counted with multiplicity) in all partitions of n.

1, 3, 5, 10, 14, 26, 35, 57, 80, 119, 161, 238, 315, 440, 589, 801, 1048, 1407, 1820, 2399, 3087, 3998, 5092, 6545, 8263, 10486, 13165, 16562, 20630, 25773, 31897, 39546, 48692, 59960, 73423, 89937, 109553, 133439, 161840, 196168, 236843, 285816, 343667, 412950, 494702, 592063, 706671

Offset: 1

Vladeta Jovovic, Feb 16 2004

nonn

Row sums of triangle A220504. - Omar E. Pol, Jan 19 2013

			Partitions of 4 are [1,1,1,1], [1,1,2], [2,2], [1,3], [4]. 1 appears 4 times in the first, 1 twice in the second, 2 twice in the third, etc.; thus a(4)=4+2+2+1+1=10.

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 550 terms from Joerg Arndt)
F. G. Garvan, Table of a(n) for n = 1..10000 (Coefficients of Andrews spt-function)
G. E. Andrews, The number of smallest parts in the partitions of n, Journal für die reine und angewandte Mathematik, Volume 2008 Issue 624, 133-142.
Scott Ahlgren, Nickolas Andersen, Euler-like recurrences for smallest parts functions, arXiv:1402.5366
George E. Andrews, Song Heng Chan and Byungchan Kim, The Odd Moments of Ranks and Cranks, Journal of Combinatorial Theory, Series A, Volume 120, Issue 1, January 2013, Pages 77-91. - From _N. J. A. Sloane_, Sep 04 2012
G. E. Andrews, F. G. Garvan, and J. Liang, Combinatorial interpretation of congruences for the spt-function
G. E. Andrews, F. G. Garvan, and J. Liang, Self-conjugate vector partitions and the parity of the spt-function
William Y.C. Chen, The spt-Function of Andrews, arXiv:1707.04369 [math.CO], Jul 14 2017.
A. Folsom and K. Ono, The spt-function of Andrews, PNAS, December 23 2008, 105 (51) 20152-20156.
F. G. Garvan, Congruences for Andrews' smallest parts partition function and new congruences for Dyson's rank
F. G. Garvan, Congruences for Andrews' spt-function modulo powers of 5, 7 and 13, arXiv:1011.1955 [math.NT], Nov 9 2010.
F. G. Garvan, Congruences for Andrews' spt-function modulo 32760 and extension of Atkin's Hecke-type partition congruences, arXiv:1011.1957 [math.NT], Nov 9 2010.
F. G. Garvan, Higher Order Spt-functions, Adv. Math. 228 (2011), no. 1, 241-265. - From _N. J. A. Sloane_, Jan 02 2013
F. G. Garvan, The smallest parts partition function, 2012.
F. G. Garvan, Dyson's rank function and Andrews's SPT-function, slides 11, 12.
M. H. Mertens, K. Ono, L. Rolen, Mock modular Eisenstein series with Nebentypus, arXiv:1906.07410 [math.NT], 2019.
K. Ono, Congruences for the Andrews spt-function, PNAS, December 21 2010, 108 (2) 473-476.
Omar E. Pol, Illustration of initial terms
Wikipedia, Spt function

Cf. A092314, A092322, A092309, A092321, A092313, A092310, A092311, A092268, A006128, A195053.

For higher-order spt functions see A221140-A221144.

b:= proc(n, i) option remember; `if`(n=0 or i=1, n,
      `if`(irem(n, i, 'r')=0, r, 0)+add(b(n-i*j, i-1), j=0..n/i))
    end:
a:= n-> b(n, n):
seq(a(n), n=1..60);  # Alois P. Heinz, Jan 16 2013

terms = 47; gf = Sum[x^n/(1 - x^n)*Product[1/(1 - x^k), {k, n, terms}], {n, 1, terms}]; CoefficientList[ Series[gf, {x, 0, terms}], x] // Rest (* Jean-François Alcover, Jan 17 2013 *)
b[n_, i_] := b[n, i] = If[n==0 || i==1, n, {q, r} = QuotientRemainder[n, i]; If[r==0, q, 0] + Sum[b[n-i*j, i-1], {j, 0, n/i}]]; a[n_] := b[n, n]; Table[a[n], {n, 1, 60}] (* Jean-François Alcover, Nov 23 2015, after Alois P. Heinz *)

N = 66;  x = 'x + O('x^N);
gf = sum(n=1,N, x^n/(1-x^n) * prod(k=n,N, 1/(1-x^k) )  );
v = Vec(gf)
/* Joerg Arndt, Jan 12 2013 */

G.f.: Sum_{n>=1} x^n/(1-x^n) * Product_{k>=n} 1/(1-x^k).
a(n) = A000070(n-1) + A195820(n). - Omar E. Pol, Oct 19 2011
a(n) = n*p(n) - N_2(n)/2 = n*A000041(n) - A220908(n)/2 = A066186(n) - A220907(n) = (A220909(n) - A220908(n))/2 = A211982(n)/2 (from Andrews's paper and Garvan's paper). - Omar E. Pol, Jan 03 2013
a(n) = A000041(n) + A000070(n-2) + A220479(n), n >= 2. - Omar E. Pol, Feb 16 2013
Asymptotics (Bringmann-Mahlburg, 2009): a(n) ~ exp(Pi*sqrt(2*n/3)) / (Pi*sqrt(8*n)) ~ sqrt(6*n)*A000041(n)/Pi. - Vaclav Kotesovec, Jul 30 2017

More terms from Pab Ter (pabrlos(AT)yahoo.com), May 25 2004

A220909 The second crank moment function M_2(n).

Original entry on oeis.org

0, 2, 8, 18, 40, 70, 132, 210, 352, 540, 840, 1232, 1848, 2626, 3780, 5280, 7392, 10098, 13860, 18620, 25080, 33264, 44088, 57730, 75600, 97900, 126672, 162540, 208208, 264770, 336240, 424204, 534336, 669438, 837080, 1041810, 1294344, 1601138, 1977140, 2432430, 2987040, 3655806

Offset: 0

N. J. A. Sloane, Jan 02 2013

nonn

M_2(n) is defined to be Sum_{m=-n..n} m^2 M(m,n) where M(m,n) is the number of partitions of n with crank m except for n=1 where M(-1,1) = M(1,1) = -M(0,1) = 1. - Michael Somos, Nov 10 2013
From Omar E. Pol, Jul 25 2022: (Start)
Apart from the initial zero this is also:
Convolution of A074400 and A000041.
Convolution of A000203 and A139582. (End)

			G.f. = 2*x + 8*x^2 + 18*x^3 + 40*x^4 + 70*x^5 + 132*x^6 + 210*x^7 + ...
For n=1, M_2(1) = Sum_{m=-1..1} m^2 * M(m,2) = (-1)^2*1 + 0^2*(-1) + 1^2*1 = 2. For n=2, the partition [2] has crank 2 and partition [1,1] has crank -2, hence M_2(2) = 2^2 + (-2)^2 = 8. - _Michael Somos_, Nov 10 2013

G. C. Greubel, Table of n, a(n) for n = 0..5000
F. G. Garvan, Higher-order spt functions, arXiv:1008.1207 [math.NT], 2010.
F. G. Garvan, Higher-order spt functions, Adv. Math. 228 (2011), no. 1, 241-265.
Wikipedia, Crank of a partition

Cf. A000041, A066186, A092269, A220908.

Cf. A000203, A074400, A139582.

a[ n_] := 2 n PartitionsP @ n (* Michael Somos, Nov 10 2013 *)

{a(n) = if( n<0, 0, 2 * n * polcoeff( 1 / eta(x + x * O(x^n)), n))} /* Michael Somos, Nov 10 2013 */

a(n) = 2*n*A000041(n) = 2*A066186(n).
a(n) = n*A139582(n). - Omar E. Pol, Jan 03 2013
a(n) = A220908(n) + A211982(n), n >= 1. - Omar E. Pol, Jan 17 2013
a(n) = 2*(A092269(n) + A220907(n)), n >= 1. _Omar E. Pol, Feb 18 2013
a(n) ~ exp(Pi*sqrt(2*n/3))/(2*sqrt(3)) * (1 - (sqrt(3/2)/Pi + Pi/(24*sqrt(6))) / sqrt(n)). - Vaclav Kotesovec, Oct 24 2016

A220908 The second rank moment function N_2(n).

Original entry on oeis.org

0, 2, 8, 20, 42, 80, 140, 238, 380, 602, 910, 1372, 1996, 2900, 4102, 5790, 8002, 11046, 14980, 20282, 27090, 36092, 47546, 62510, 81374, 105700, 136210, 175084, 223510, 284694, 360410, 455244, 572054, 717160, 894964, 1114470, 1382032, 1710262, 2108750, 2594704, 3182120

Offset: 1

N. J. A. Sloane, Jan 02 2013

nonn

N_2(n) is also called the second Atkin-Garvan moment (see Andrews' paper). - Omar E. Pol, Oct 23 2013

Alois P. Heinz, Table of n, a(n) for n = 1..1000
G. E. Andrews, The number of smallest parts in the partitions of n, p. 3
F. G. Garvan, Higher-order spt functions, Adv. Math. 228 (2011), no. 1, 241-265. See Eq. (1.1).

Cf. A000041, A092269, A220907.

b:= proc(n, i) option remember; `if`(n=0 or i<1, 0,
      `if`(irem(n, i, 'r')=0, r, 0)+add(b(n-i*j, i-1), j=0..n/i))
    end:
a:= n-> 2*(n*combinat[numbpart](n)- b(n, n)):
seq(a(n), n=1..60);  # Alois P. Heinz, Jan 09 2013

terms = 41; gf = Sum[x^n/(1 - x^n)*Product[1/(1 - x^k), {k, n, terms}], {n, 1, terms}]; spt = CoefficientList[ Series[gf, {x, 0, terms}], x] // Rest; a[n_] := 2*(n*PartitionsP[n] - spt[[n]]); Table[a[n], {n, 1, terms}] (* Jean-François Alcover, Jan 17 2013, after g.f. of spt(n) *)

a(n) = 2*A220907(n) = 2*(n*A000041(n)-A092269(n)).
a(n) = 2*(A066186(n) - A092269(n)). - Omar E. Pol, Jan 09 2013
a(n) = A220909(n) - A211982(n). - Omar E. Pol, Jan 16 2013
a(n) ~ exp(Pi*sqrt(2*n/3))/(2*sqrt(3)) * (1 - (3*sqrt(6)/(2*Pi) + Pi/(24*sqrt(6)))/sqrt(n) + (5/48 + Pi^2/6912)/n). - Vaclav Kotesovec, Jul 31 2017

A211982 Second crank moment minus second rank moment: M_2(n) - N_2(n) = 2*spt(n).

Original entry on oeis.org

2, 6, 10, 20, 28, 52, 70, 114, 160, 238, 322, 476, 630, 880, 1178, 1602, 2096, 2814, 3640, 4798, 6174, 7996, 10184, 13090, 16526, 20972, 26330, 33124, 41260, 51546, 63794, 79092, 97384, 119920, 146846, 179874, 219106, 266878, 323680, 392336, 473686

Offset: 1

Omar E. Pol, Jan 03 2013

nonn

Also total number of smallest parts in all partitions of n, multiplied by 2.

Alois P. Heinz, Table of n, a(n) for n = 1..1000
G. E. Andrews, The number of smallest parts in the partitions of n
F. G. Garvan, Congruences for Andrews' smallest parts partition function and new congruences for Dyson's rank
F. G. Garvan, Higher order spt-functions

Cf. A092269, A066186, A220907, A220908, A220909.

b:= proc(n, i) option remember; `if`(n=0 or i=1, n,
      `if`(irem(n, i, 'r')=0, r, 0)+add(b(n-i*j, i-1), j=0..n/i))
    end:
a:= n-> 2* b(n, n):
seq(a(n), n=1..60);  # Alois P. Heinz, Jan 17 2013

terms = 41; gf = Sum[x^n/(1 - x^n)*Product[1/(1 - x^k), {k, n, terms}], {n, 1, terms}]; 2*CoefficientList[ Series[gf, {x, 0, terms}], x] // Rest (* Jean-François Alcover, Jan 17 2013, from 2nd formula *)

a(n) = A220909(n) - A220908(n) = 2*A092269(n).

a(n) ~ exp(Pi*sqrt(2*n/3)) / (Pi*sqrt(2*n)) * (1 - Pi/(24*sqrt(6*n)) + (144+Pi^2)/(6912*n)). - Vaclav Kotesovec, Jul 31 2017

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A092269 Spt function: total number of smallest parts (counted with multiplicity) in all partitions of n.

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A220909 The second crank moment function M_2(n).

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A220908 The second rank moment function N_2(n).

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A211982 Second crank moment minus second rank moment: M_2(n) - N_2(n) = 2*spt(n).

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