A377075 -id:A377075 - cp's OEIS frontend

A350889 Triangle T(n,k), n >= 1, 1 <= k <= n, read by rows, where T(n,k) is the number of partitions of n such that k*(smallest part) = (number of parts).

1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 3, 3, 2, 1, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 2, 4, 5, 5, 3, 2, 1, 1, 2, 3, 4, 7, 6, 5, 3, 2, 1, 1, 3, 4, 5, 8, 9, 7, 5, 3, 2, 1, 1, 3, 5, 6, 10, 11, 10, 7, 5, 3, 2, 1, 1, 4, 6, 7, 12, 15, 13, 11, 7, 5, 3, 2, 1, 1, 4, 8, 8, 14, 18, 18, 14, 11, 7, 5, 3, 2, 1, 1

Offset: 1

Seiichi Manyama, Jan 21 2022

Column k is asymptotic to r^2 * (k*log(r)^2 + polylog(2, r^2))^(1/4) * exp(2*sqrt((k*log(r)^2 + polylog(2, r^2))*n)) / (2*sqrt(Pi*k*(k - (k-2)*r^2)) * n^(3/4)), where r is the positive real root of the equation r^2 = 1 - r^k. - Vaclav Kotesovec, Oct 14 2024

			Triangle begins:
  1;
  0, 1;
  0, 1, 1;
  1, 1, 1, 1;
  1, 1, 2, 1, 1;
  1, 1, 2, 2, 1, 1;
  1, 1, 3, 3, 2, 1, 1;
  1, 2, 3, 4, 3, 2, 1, 1;
  2, 2, 4, 5, 5, 3, 2, 1, 1;
  2, 3, 4, 7, 6, 5, 3, 2, 1, 1;
  3, 4, 5, 8, 9, 7, 5, 3, 2, 1, 1;

Andrew Howroyd, Table of n, a(n) for n = 1..1275 (rows 1..50).

Row sums give A168657.
Column k=1..8 give A006141, A237757, A350892, A350896, A350897, A377076, A377077, A377075.
Cf. A350879, A350890.

T(n, k) = polcoef(sum(i=1, sqrtint(n\k), x^(k*i^2)/prod(j=1, k*i-1, 1-x^j+x*O(x^n))), n);

def partition(n, min, max)
  return [[]] if n == 0
  [max, n].min.downto(min).flat_map{|i| partition(n - i, min, i).map{|rest| [i, *rest]}}
end
def A(n)
  a = Array.new(n, 0)
  partition(n, 1, n).each{|ary|
    (1..n).each{|i|
      a[i - 1] += 1 if i * ary[-1] == ary.size
    }
  }
  a
end
def A350889(n)
  (1..n).map{|i| A(i)}.flatten
end
p A350889(14)

G.f. of column k: Sum_{i>=1} x^(k*i^2)/Product_{j=1..k*i-1} (1-x^j).

A376658 Decimal expansion of a constant related to the asymptotics of A376624 and A376625.

Original entry on oeis.org

8, 4, 6, 0, 1, 8, 7, 2, 4, 4, 2, 5, 2, 9, 6, 4, 8, 0, 9, 7, 5, 2, 3, 0, 0, 0, 9, 8, 8, 8, 9, 1, 7, 5, 9, 4, 3, 3, 5, 4, 7, 0, 6, 3, 5, 9, 5, 1, 0, 1, 4, 3, 6, 7, 6, 2, 2, 8, 2, 1, 1, 5, 8, 9, 0, 4, 3, 2, 1, 4, 9, 8, 2, 7, 8, 2, 6, 0, 7, 4, 4, 5, 0, 9, 6, 6, 7, 2, 6, 4, 2, 9, 6, 3, 0, 6, 8, 0, 4, 9, 8, 4, 4, 5, 7

Offset: 1

Vaclav Kotesovec, Oct 01 2024

			8.46018724425296480975230009888917594335470635951014367622821158904321498...

Cf. A072223, A333198, A376621, A376624, A376625, A376659, A376660, A377075.

Cf. A356032.

RealDigits[E^(Sqrt[2*Log[r]^2 + 4*PolyLog[2, Sqrt[r]]]) /. r -> 1/(2*Sqrt[3/(4 + ((155 - 3*Sqrt[849])/2)^(1/3) + ((155 + 3*Sqrt[849])/2)^(1/3))]) - Sqrt[8/3 - ((155 - 3*Sqrt[849])/2)^(1/3)/3 - ((155 + 3*Sqrt[849])/2)^(1/3)/3 + 2*Sqrt[3/(4 + ((155 - 3*Sqrt[849])/2)^(1/3) + ((155 + 3*Sqrt[849])/2)^(1/3))]]/2, 10, 105][[1]]

Equals exp(sqrt(2*(log(r)^2 + 2*polylog(2, sqrt(r))))), where r = A072223 = 0.52488859865640479389948613854128391569... is the smallest real root of the equation (1 - r^2)^2 = r.
Equals limit_{n->infinity} A376624(n)^(1/sqrt(n)).
Equals limit_{n->infinity} A376625(n)^(1/sqrt(n)).
Equals limit_{n->infinity} A377075(n)^(1/sqrt(n)).
Equals exp(2*sqrt(2*log(A356032)^2 + polylog(2, A356032))).

cp's OEIS Frontend

A350889 Triangle T(n,k), n >= 1, 1 <= k <= n, read by rows, where T(n,k) is the number of partitions of n such that k*(smallest part) = (number of parts).

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