221100

Appears in sequences

• Ternary numbers with equal numbers of 0's, 1's and 2's and such that read left-to-right at all times the number of 2's >= number of 1's >= number of 0's.at n=5A134236
• a(n) = n*(1 + n)*(3 - 4*n + 4*n^2)/6.at n=23A213840
• Number of ways of writing n as the sum of 11 triangular numbers.at n=20A226255
• Ternary numbers consisting of a run of 2's, then a run of 1's, then a run of 0's.at n=15A371053
• Ternary numbers that are concatenated runs C(1)A(1)B(1)C(2)A(2)B(2)...C(k)A(k)B(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.at n=16A371111