A283720 Main diagonal of A283675.

1, -1, -16, -19619, -4294403215, -298022109672568357, -10314423865939993706950978963, -256923577039780637227768848162543179896514, -6277101735175091675863380669683250419973895230549186236030

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..26

Mathematica

Table[SeriesCoefficient[Product[(1 - x^k)^(k^(n*k)), {k, 1, 10}], {x, 0, n}], {n, 0, 10}] (* Indranil Ghosh, Mar 17 2017 *)

Prog

(Ruby)
def s(k, i)
  s = 0
  (1..i).each{|j| s += j ** (k * j + 1) if i % j == 0}
  s
end
def A(k, n)
  ary = [1]
  s_ary = [0] + (1..n).map{|i| s(k, i)}
  (1..n).each{|i| ary << (1..i).inject(0){|s, j| s - ary[-j] * s_ary[j]} / i}
  ary
end
def A283720(n)
  (0..n).map{|i| A(i, i)[-1]}
end

Crossrefs

Cf. A283675.

Sequence in context: A214637 A288957 A159387 * A349891 A098175 A089232

Adjacent sequences: A283717 A283718 A283719 * A283721 A283722 A283723

Keyword

sign

Author

Seiichi Manyama, Mar 15 2017

Status

approved