43687

Appears in sequences

• Number of Barlow packings with group P3(bar)m1(SO) that repeat after 2n-1 layers.at n=17A011950
• Expansion of 1/((1-x)(1-6x)(1-12x)).at n=4A016248
• Composite numbers whose prime factors have no digits other than 7's and 9's.at n=17A036324
• Row sums of array T as in A054110.at n=14A054111
• Sum of the prime factors of k equals half the sum of the prime factors of k + 1.at n=20A074213
• Number of semi-magic 3-dimensional hypercubes with 27 entries and magic sum n.at n=6A111085
• a(0) = 3, a(1) = 5, a(2) = 1, and a(n) = (2^(1 + n) - 11*(-1)^n)/3 for n > 2.at n=16A115335
• Numbers n such that (6k-1) for k=n, n+1, n+2, n+3 are all primes with no primes of the form (6k+1) in between.at n=38A296011
• a(n) = Sum_{k=1..n} k^2*tau(k), where tau is A000005.at n=30A319085
• a(n) + a(n+1) = 2^n for n >= 0 with a(0) = 4.at n=17A352692
• Numbers that can be written as a^2 + 3*b^2 for some a, b in A155716 and also as c^2 + 6*d^2 for some c, d in A092572.at n=33A380295
• Numbers k such that sigma(k) = psi(k) + tau(k) + omega(k).at n=20A386637