69006

Appears in sequences

• Numbers k such that 8^k == -1 (mod k-1).at n=18A055691
• Triangular numbers using only the curved digits 0, 3, 6, 8 and 9.at n=17A079653
• Triangular numbers whose sum of squared digits is also triangular.at n=25A094890
• Triangular numbers all of whose digits are nonprimes.at n=33A111484
• Triangular numbers composed of digits {0,6,9}.at n=5A119091
• Triangular numbers which are an average of four consecutive primes.at n=33A226196
• The first of two consecutive triangular numbers the sum of which is equal to the sum of two consecutive prime numbers.at n=23A298462
• 4*a(n) is the maximum possible determinant of a 3 X 3 matrix whose entries are 9 consecutive primes starting with prime(n).at n=25A340923
• Number of transitive relations on an n-set with exactly four ordered pairs.at n=7A349849
• Triangular numbers which are products of five distinct primes.at n=20A357590