20659

Appears in sequences

• Number of 6-ary rooted trees with n nodes and height exactly 6.at n=15A036644
• a(n) = ceiling(a(n-1)/2) + a(n-2) with a(0)=0 and a(1)=1.at n=40A064651
• The number of possible values of the squarefree kernel (A007947) shared by at least two solutions x to A056239(x) = n.at n=52A088318
• A musically inspired Titius-Bode-like sequence based on the geometric division of 4- and 5-dimensional space: Z_(n+1) = 3 * (C(n-1, 0) + C(n-1, 1) + C(n-1, 2) + C(n-1, 3) + C(n-1, 4) + C(n-1, 5)*A059620(n+6)) + 4.at n=17A209257
• Expansion of Sum_{k>=0} x^(k*(k+1)) / Product_{j=1..k} (1 - x^j)^j.at n=43A306664
• Number of planar distributive lattices with n nodes.at n=20A343161