18515

Appears in sequences

• a(0) = 1, a(n) = 17*n^2 + 2 for n>0.at n=33A010007
• a(n) = (2*n - 11)*n^2.at n=23A015245
• Discriminants of totally complex sextic fields (negated).at n=10A023687
• Product of n with sum of next n consecutive integers.at n=22A036659
• Triangle T(n,k) read by rows giving number of labeled mappings (or functional digraphs) from n points to themselves (endofunctions) with exactly k cycles, k=1..n.at n=24A060281
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=5, k=-1 and l=0.at n=7A176859
• Numbers that match polynomials over {0,1} that have a factor containing -3 as a coefficient; see Comments.at n=25A208182
• Least k such that the sum of the semiprime divisors equals n times the sum of the prime divisors, or 0 if no such k exists.at n=22A227419
• Composite numbers k such that sigma(k + sigma(k)) = 2*sigma(k).at n=22A246858
• Numbers n for which the digital sum contains the same distinct digits as the digital product but the digital sum is not equal to the digital product.at n=29A249335
• Expansion of (4 + 15*x - 35*x^2 + 20*x^3 - 2*x^5)/(1 - x)^5.at n=17A257600
• a(n) = (n^4 + 20*n^3 + 125*n^2 + 250*n + 24)/12.at n=17A257601
• Number of endofunctions on [n] with exactly four cycles.at n=3A273435
• Triangle T(n, m) appearing in the expansion of the scaled phase space coordinate qhat of the plane pendulum in terms of the Jacobi nome q and sin(v) multiplying even powers of 2*cos(v), with v = u/((2/Pi)*K(k)).at n=25A275790