99009

Appears in sequences

• a(n) = Sum_{k=0..n} C(n-k,4*k).at n=21A005676
• Base 8 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,1.at n=5A037650
• Smallest multiple of n using only digits 0 and 9.at n=18A078248
• Numbers whose set of base 10 digits is {0,9}.at n=25A097256
• a(n) = (16/3)*(n+1)*n*(n-1) + 8*n^2 + 1.at n=25A212668
• Principal diagonal of the convolution array A212891.at n=17A213436
• Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section.at n=29A278457
• Number of compositions of 5*n-1 into parts 4 and 5.at n=16A369849
• a(n) = Sum_{k=0..floor(n/2)} binomial(k,2*(n-2*k)).at n=42A392250