1825200

Appears in sequences

• Numbers k such that the standard deviation of 1,...,k is an integer.at n=6A007654
• Numbers k such that k and k+1 are powerful numbers.at n=8A060355
• Powerful numbers of the form k^2 - 1.at n=6A060859
• a(n) = sinh(2*arccosh(n))^2 = 4*n^2*(n^2 - 1).at n=26A173121
• a(n) = sinh^2( 2n*arcsinh(sqrt n)).at n=3A173175
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where A(n,k) is 1/2 * (-1 + Sum_{j=0..k} binomial(2*k,2*j)*(n+1)^(k-j)*n^j).at n=48A322699
• Smaller of a pair of numbers (m, m+1) such that both are products P of composite prime powers with omega(P) > 1.at n=4A358174
• The smaller of a pair of successive powerful numbers without a nonsquarefree number between them.at n=20A371190
• a(n) is the least exponential deficient number that has exactly n exponential abundant divisors.at n=10A389300