28311552

Appears in sequences

• First differences of A045623.at n=23A045891
• Table of resultants for Hermite polynomials H_k(x) and H_n(x).at n=8A054373
• a(n) = (3^3)*4^(n-3) with a(0)=1, a(1)=1 and a(2)=7.at n=13A056120
• A hierarchical sequence (S(W'2{3}*c) - see A059126).at n=17A059162
• Maximal number of divisors of any n-digit number.at n=31A066150
• Composites of form prime-1 containing a record number of prime factors.at n=18A066632
• Let M_n be the n X n matrix m(i,j) = min(prime(i), prime(j)); then a(n) = det(M_n).at n=15A070323
• a(1)=1, then a(n)=3*a(n-1) if n is already in the sequence, a(n)=2*a(n-1) otherwise.at n=23A079352
• Product ceiling(n/1)*ceiling(n/2)*ceiling(n/3)*...*ceiling(n/n) (the 'ceiling factorial').at n=16A131385
• Expansion of (1+8x^2+8x^3)/((1-2x)^2*(1+2x+4x^2)).at n=20A168057
• a(n) = 27*2^n.at n=20A175806
• Hankel transform of Thue-Morse related sequence A106400.at n=21A186026
• 3-smooth numbers k such that k+1 and (k+2)/2 are prime.at n=12A325255
• 30*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=23A337881
• a(n) = coefficient of x^(2*n) in C(x) defined by: C(x) + i*S(x) = Sum_{n=-oo..+oo} i^n * (2*x)^(n^2) * F(x)^n, where F(x) is the g.f. of A357787 such that C(x)^2 + S(x)^2 = 1.at n=9A357788
• a(n) is the first number == 1 (mod n) that is the product of n primes, counted by multiplicity.at n=22A368217
• a(n) is the least k such that the sum of k and the k-th number with n prime factors (counted with multiplicity) has n prime factors (counted with multiplicity).at n=24A381630