1638400

Appears in sequences

• First differences of A045891.at n=20A034007
• a(n) = (3*n-1) * 2^(n-2).at n=16A053220
• Products of exactly 18 primes (generalization of semiprimes).at n=11A069279
• 8th binomial transform of (1,7,0,0,0,0,0,...).at n=6A081043
• a(0)=0; for n > 0, a(n) = (n+1)^(n-2)*2^(n^2).at n=4A086804
• Second differences of A045623, prefixed by an initial 1.at n=19A109975
• Number of 3 X 3 symmetric matrices over Z(n) having determinant 0.at n=15A115223
• Number of binary strings of length n with equal numbers of 0001 and 1000 substrings.at n=21A164161
• Totally multiplicative sequence with a(p) = 8*(p+2) for prime p.at n=35A167309
• (n-1)-st elementary symmetric function of the first n terms of (1,2,1,2,1,2,1,2,1,2,...)=A000034.at n=32A203150
• Number of n X n 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=7A208063
• Numbers m for which sum of divisors of sum of divisors of m is a power of 2.at n=19A275674
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 334", based on the 5-celled von Neumann neighborhood.at n=22A287737
• Squares that can be expressed as the sum of two positive squares but not as the sum of three positive squares.at n=8A309779
• a(n)=(-1)^((n-2)*(n-1)/2)*2^((n-1)^2)*n^(n-3).at n=4A317450
• Total number of neighbor contacts for n-step self-avoiding walks on a 2D square lattice.at n=12A336492
• 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=18A337882
• a(n) = Product_{k=0..9} floor((n+k)/10).at n=42A354600
• a(n) is the index of the smallest square pyramidal number with exactly n prime factors (counted with multiplicity).at n=26A359193
• a(n) is the number of divisors of n^n - n.at n=35A377676