33411

Appears in sequences

• Triangular numbers such that the product of digits is also a (positive) triangular number.at n=17A069077
• Triangular numbers whose sum of squared digits is also triangular.at n=19A094890
• Triangular numbers for which the sum of the digits is a pentagonal number.at n=27A117305
• Triangular numbers composed of digits {1,3,4}.at n=3A119111
• Numerator of determinant of n X n matrix with elements M[i,j] = (p^2 - p + 1)/(p*(p-1)) if i=j and 1 otherwise, where p=Prime[i].at n=4A119958
• Triangular numbers t which are average of two consecutive primes p and p+4.at n=27A129752
• a(n) = (4*n^3 - 9*n^2 + 11*n + 3)/3.at n=30A161707
• The positions of zeros in A163898 and A163899.at n=35A165403
• Least triangular number of the form p*triangular(n) where p is a prime number, or 0 if no such triangular number exists.at n=42A225789
• Triangular numbers that are the product of a triangular number and a prime number.at n=47A253651
• Numbers m such that there are precisely 19 groups of order m.at n=17A298910
• Triangular numbers that are the product of four distinct primes.at n=38A333771