A064173 Number of partitions of n with positive rank.
0, 1, 1, 2, 3, 5, 6, 10, 13, 19, 25, 35, 45, 62, 80, 106, 136, 178, 225, 291, 366, 466, 583, 735, 912, 1140, 1407, 1743, 2140, 2634, 3214, 3932, 4776, 5807, 7022, 8495, 10225, 12313, 14762, 17696, 21136, 25236, 30030, 35722, 42367, 50216, 59368, 70138, 82665
Offset: 1
Keywords
Examples
a(20) = p(18) - p(13) + p(5) = 385 - 101 + 7 = 291. From _Gus Wiseman_, Feb 09 2021: (Start) The a(2) = 1 through a(9) = 13 partitions of positive rank: (2) (3) (4) (5) (6) (7) (8) (9) (31) (32) (33) (43) (44) (54) (41) (42) (52) (53) (63) (51) (61) (62) (72) (411) (421) (71) (81) (511) (422) (432) (431) (441) (521) (522) (611) (531) (5111) (621) (711) (5211) (6111) (End)
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..10000
- F. J. Dyson, Some guesses in the theory of partitions, Eureka (Cambridge) 8 (1944), 10-15.
- FindStat, St000145: The Dyson rank of a partition
- Mircea Merca, Rank partition functions and truncated theta identities, arXiv:2006.07705 [math.CO], 2020.
Crossrefs
Note: A-numbers of ranking sequences are in parentheses below.
These partitions are ranked by (A340787).
A072233 counts partitions by sum and length.
A168659 counts partitions whose length is a multiple of the greatest part.
A200750 counts partitions whose length and greatest part are coprime.
- Rank -
A257541 gives the rank of the partition with Heinz number n.
- Balance -
A340599 counts alt-balanced factorizations.
A340653 counts balanced factorizations.
Programs
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Maple
A064173 := proc(n) a := 0 ; for p in combinat[partition](n) do r := max(op(p))-nops(p) ; if r > 0 then a := a+1 ; end if; end do: a ; end proc: seq(A064173(n),n=0..40) ;# Emeric Deutsch, Dec 11 2004
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Mathematica
Table[Count[IntegerPartitions[n], q_ /; First[q] > Length[q]], {n, 24}] (* Clark Kimberling, Feb 12 2014 *) Table[Count[IntegerPartitions[n], p_ /; ! MemberQ[p, Max[Max[p], Length[p]]]], {n, 20}] (* Clark Kimberling, Feb 28 2014 *) P = PartitionsP; a[n_] := (P[n] - Sum[-(-1)^k (P[n - (3k^2 - k)/2] - P[n - (3k^2 + k)/2]), {k, 1, Floor[(1 + Sqrt[1 + 24n])/6]}])/2; a /@ Range[48] (* Jean-François Alcover, Jan 11 2020, after Wouter Meeussen in A047993 *)
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PARI
my(N=66, x='x+O('x^N)); concat(0, Vec(sum(k=1, N, x^k*prod(j=1, k, (1-x^(k+j-2))/(1-x^j))))) \\ Seiichi Manyama, Jan 25 2022
Formula
a(n) = p(n-2) - p(n-7) + p(n-15) - ... - (-1)^k*p(n-(3*k^2+k)/2) + ..., where p() is A000041(). - Vladeta Jovovic, Aug 04 2004
G.f.: Product_{k>=1} (1/(1-q^k)) * Sum_{k>=1} ( (-1)^k * (-q^(3*k^2/2+k/2))) (conjectured). - Thomas Baruchel, May 12 2018
G.f.: Sum_{k>=1} x^k * Product_{j=1..k} (1-x^(k+j-2))/(1-x^j). - Seiichi Manyama, Jan 25 2022
Comments