278460

Appears in sequences

• a(n) = (2*n-1)*(3*n-1)*(4*n-1).at n=23A033589
• Denominator of sum of first n terms of the series 1/15 + 1/63 + 1/80 ... in which the denominators are perfect squares - 1 which are simultaneously other powers, e.g. a(1) = 15 because 16 = 4^2 = 2^4, a perfect square that is also a fourth power; hence 16-1 = 15 qualifies as a term.at n=4A062757
• Seventh column of Catalan triangle A009766.at n=16A064059
• Triangle T(n,k), 1<=k<=n, read by rows given by T(n,k) = A003266(n)/A000045(k).at n=41A121284
• a(1)=1. For n>1, a(n) is the smallest even number such that every subset of a(1), ..., a(n) adds to a nonprime.at n=8A128688
• Numbers with prime factorization pqrst^2u^2.at n=3A190380
• Denominators of partial sums of 1/A216765(n).at n=5A216767
• Number of ways of arranging n chords on a circle (handshakes between 2n people across a table) with exactly 3 simple intersections.at n=9A232224
• Number of ways to place 3 points on a triangular grid of side n so that they are not vertices of an equilateral triangle of any orientation.at n=14A240440
• Numbers n such that there exists an x!=n that makes {x,x,n} an amicable multiset.at n=18A259303
• Number T(n,k) of modified skew Dyck paths of semilength n with exactly k anti-down steps; triangle T(n,k), n>=0, 0<=k<=n-floor((1+sqrt(max(0,8n-7)))/2), read by rows.at n=46A274404