48427561

Appears in sequences

• a(n) = (9^n - 1)/8.at n=9A002452
• Coloring a circuit with 4 colors.at n=17A006342
• Gaussian binomial coefficients [ n,8 ] for q = 9.at n=1A022259
• a(n) = n^0 + n^1 + ... + n^(n-1), or a(n) = (n^n-1)/(n-1) with a(0)=0; a(1)=1.at n=9A023037
• Base-3 digits are, in order, the first n terms of the periodic sequence with initial period 1,0.at n=16A033113
• a(n) = floor(9^9/n).at n=7A057071
• Numbers of the form (9^{mr}-1)/(9^r-1) for positive integers m, r.at n=20A076288
• Triangle read by rows: T(n,k) = (n+1,k)-th element of (M^9-M)/8, where M is the infinite lower Pascal's triangle matrix, 1<=k<=n.at n=36A096043
• a(n) = Sum_{k=0..floor(n/2)} binomial(n-k, k-1)*2^(n-k-1)*(3/2)^(k-1).at n=18A099583
• a(n) = Sum_{j=0..8} n^j.at n=9A102909
• If n mod 2 = 0 then (3^(n+3)-19)/8 else (3^(n+3)-1)/8.at n=15A116973
• Triangle read by rows: T(n,k) = value of the n-th repunit in base (k+1) representation, 1<=k<=n.at n=43A125118
• a(n) = (3^n-1)/2 if n odd, (3^n-1)/8 if n even.at n=18A152298
• A threes sequence that gets more even factors out: a(n) = (3^n - 1)*(3^n + 1)/2^(4 - (n mod 2)).at n=9A152299
• Fermat pseudoprimes to base 3 of the form (3^(4*k + 2) - 1)/8.at n=3A217853
• Expansion of 1/((x-1)*(3*x-1)*(3*x^2+1)).at n=16A239577
• E.g.f. A(x,k) satisfies: sin(A(x,k)) = k * sin(x).at n=46A291560
• a(n) = p(0,n), where p(x,n) is the strong divisibility sequence of polynomials based on sqrt(3) as in A327321.at n=17A329008
• Triangular numbers that are palindromes in base 3.at n=13A350990
• Triangular numbers that are palindromes in base 9.at n=25A350993