31930

Appears in sequences

• 9-gonal (or enneagonal) pyramidal numbers: a(n) = n*(n+1)*(7*n-4)/6.at n=30A007584
• a(n) = binomial(n,4) + binomial(n,2).at n=30A055795
• a(1) = 2. For n>1, a(n) = smallest m such that m == 0 (mod prime(n)), m + 1 == 0 (mod prime(n+1)) and m-1 == 0 (mod prime(n-1)).at n=10A078455
• a(n) = (2*n^3 + 5*n^2 - 17*n)/2.at n=30A162259
• Number of -n..n arrays x(0..6) of 7 elements with zero sum and no two consecutive declines, no adjacent equal elements, and no element more than one greater than the previous (random base sawtooth pattern).at n=38A200185
• Even 9-gonal (nonagonal) pyramidal numbers.at n=21A218329
• Numbers k such that k and k+1 are both terms in A377732.at n=25A377733