13589544960domain: NAppears in sequencesa(n) = n*(n+3)*2^(n-3).at n=26A001793Coefficients of Chebyshev polynomials: n*(2*n-3)*2^(2*n-5).at n=13A002698a(n) = Product_{i=2..n} phi(i)/bigomega(i).at n=19A06698830*a(n) + 1 is the least prime of the form 2^r*3^s*5^t + 1, r > 0, s > 0, t > 0, r + s + t = n.at n=30A337882