31940

Appears in sequences

• Fibonacci sequence beginning 0, 20.at n=17A022354
• Numerators of continued fraction convergents to sqrt(399).at n=5A041758
• Numbers n such that (digital sum of n)^3 = reversal of n. (Powers of 10 excluded.)at n=6A085754
• Values of z in solutions (x,y,z) to the Diophantine equation x^3-x^2+y^3-y^2=z^3-z^2, with 1<x<y<z arranged in order of increasing x.at n=28A138669
• a(n) = ChebyshevT(3, n).at n=20A144129
• a(n) = (n+3)^2*n/2 + 1.at n=38A154560
• a(n) + a(n+2) = n^3.at n=40A206481
• a(n) = n^3 - a(n-2) for n >= 2 and a(0)=0, a(1)=1.at n=39A215097
• Number of nX3 integer arrays with each element equal to the number of horizontal, vertical, diagonal and antidiagonal neighbors less than itself.at n=3A265957
• Number of n X 4 integer arrays with each element equal to the number of horizontal, vertical, diagonal and antidiagonal neighbors less than itself.at n=2A265958
• T(n,k) = Number of n X k integer arrays with each element equal to the number of horizontal, vertical, diagonal and antidiagonal neighbors less than itself.at n=17A265960
• T(n,k) = Number of n X k integer arrays with each element equal to the number of horizontal, vertical, diagonal and antidiagonal neighbors less than itself.at n=18A265960
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) - b(n-2) + 1, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=19A294422
• a(n) = value of Chebyshev T-polynomial T_n(20).at n=3A322890
• a(n) = Sum_{i=1..n} sigma(i)*sigma(i+1), where sigma(n) = A000203(n) is the sum of the divisors of n.at n=32A330322
• Number of ways to write n as an ordered sum of 10 nonzero triangular numbers.at n=27A340955
• Dirichlet g.f.: Product_{k>=2} 1 / (1 - k^(-s))^binomial(k+2,3).at n=39A344203
• Expansion of 1/(1 - 2*x + 3*x^2 + 2*x^3 + x^4).at n=16A375255