21519

Appears in sequences

• Series expansion of (eta(q^9) / eta(q))^3 in powers of q.at n=14A121589
• Expansion of (eta(q)eta(q^9)/eta(q^3)^2)^6 in powers of q.at n=14A121592
• Square array, read by antidiagonals, where row n+1 equals the partial sums of the sequence resulting from removing the terms in the first column and main diagonal from row n, for n>=0, with row 0 consisting of all 1's.at n=58A130462
• a(n) = n*(2*n^2 + 5*n + 1)/2.at n=26A162254
• Expansion of q * (f(q^9) / f(q))^3 in powers of q where f() is a Ramanujan theta function.at n=14A227454
• Number of nX5 0..1 arrays with every element equal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.at n=5A297863
• Number of nX6 0..1 arrays with every element equal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.at n=4A297864
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.at n=49A297866
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.at n=50A297866
• Replacing each digit d in decimal expansion of n with d^2 yields a prime at each step when done recursively three times.at n=24A316604