159330

Appears in sequences

• Triangular numbers that are sandwiched between two semiprimes; or triangular numbers t such that t-1 and t+1 are both semiprime.at n=26A121898
• Number of -6..6 arrays x(0..n-1) of n elements with zero sum and no element more than one greater than the previous.at n=8A199845
• Matula-Goebel numbers of transitive rooted identity trees (or transitive finitary sets).at n=36A290760
• Triangular numbers which are products of five distinct primes.at n=37A357590
• Triangular numbers that are sandwiched between two squarefree semiprimes.at n=24A375384