185136

Appears in sequences

• Triangular numbers of form a(a+1)(a+2).at n=5A001219
• a(n) = (5*n + 1)*(5*n + 2)*(5*n + 3).at n=11A001509
• Left-hand border of triangle A046937.at n=10A038561
• a(n) = (5*n+9)(!^5)/9(!^5), related to A034301 ((5*n+2)(!^5) quintic, or 5-factorials).at n=4A051690
• a(n) = (2*n+2)*(2*n+3)*(2*n+4) = 24*A000330(n+1).at n=27A069074
• Triangular numbers which are 8-almost primes.at n=19A076582
• a(n) = p(n)/p(n-1), where p(n) = ( floor(n*log(n)) / Product_{j=2..pi(floor(n*log(n)))} prime(j) )!.at n=18A088301
• a(n) = (3*n-1) * 3*n * (3*n+1).at n=18A097321
• Triangular numbers t such that all the digits needed to write the consecutive triangular numbers from 0 to t fill exactly an equilateral triangle (no holes, no overlaps).at n=30A158030
• Triangular numbers that are sums of twin prime pairs.at n=21A165966
• Number of 3 X 3 magilatin squares with positive values < n.at n=14A173548
• Number of nX5 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 1 1 vertically.at n=6A207842
• Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 1 1 vertically.at n=4A207850
• Triangular numbers representable as x!/y! with y < x-1.at n=5A227027
• Smallest triangular number whose decimal expansion ends (nontrivially) with the n-th triangular number.at n=15A229262
• a(n) is the minimal k such that nextprime(2k+1) - 2k = prime(n) where nextprime(n) is least prime > n.at n=25A229512
• Number T(n,k) of entries in the k-th last blocks of all set partitions of [n]; triangle T(n,k), n>=1, 1<=k<=n, read by rows.at n=45A286416