1212751

Appears in sequences

• a(n) = Sum_{1 <= i < j <= n} (j-i)^3.at n=29A024166
• Triangle T(n,k) read by rows of the smallest n-gonal number greater than 1 that is also k-gonal, or 0 if none exists, for 3 <= k <= n.at n=34A189216
• Numbers which are both 9-gonal (nonagonal) and 10-gonal (decagonal).at n=1A203627
• Composite squarefree numbers k such that k^2-1 is divisible by p-1 and p+1, where p are all the prime factors of k.at n=19A306685
• Least nonnegative number greater than the previous number which is simultaneously an n-gonal and (n+1)-gonal number.at n=9A342300
• Numbers that are both k-gonal and (k+1)-gonal for some k >= 3.at n=9A378245