20034

Appears in sequences

• Octagonal pyramidal numbers: a(n) = n*(n+1)*(2*n-1)/2.at n=26A002414
• a(n) = (n+1)*(2*n+1)*(4*n+1).at n=13A079588
• Structured icosidodecahedral numbers.at n=13A100147
• G.f. satisfies: A(x) = 1/(1-x) * A(x^2)*A(x^3)*A(x^4)*...*A(x^n)*...at n=27A129374
• Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.at n=3A162830
• Number of 0..n arrays x(0..3) of 4 elements without any two consecutive increases or two consecutive decreases.at n=12A200839
• Number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.at n=18A207142
• Expansion of a(q) * b(q)^3 in powers of q where a(), b() are cubic AGM theta functions.at n=15A215711
• Even octagonal pyramidal numbers (A002414).at n=12A218327
• Numbers of the form x^3 + SumOfCubedDigits(x).at n=27A225051
• Sum of the denominators of the Farey series of order n (A006843).at n=46A240877
• Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 4.at n=21A241649
• Number of integer partitions of n whose multiplicities cover an initial interval of positive integers.at n=44A317081
• Irregular table read by rows: T(n,k) is the number of k-gons, k>=2, among all distinct circles that can be constructed from the 3 vertices and the equally spaced 3*n points placed on the sides of an equilateral triangle, using only a compass.at n=36A372617