223446

Appears in sequences

• Triangular numbers obtained as the concatenation of n and 2n.at n=5A226772
• Triangular numbers with digits in nondecreasing order.at n=28A234848
• Triangular numbers n such that sigma(n) is a square number.at n=17A256151
• Triangular numbers k such that psi(k) is a square, where psi(k) is the Dedekind psi function (A001615).at n=37A292064
• Number of unordered pairs of strict integer partitions of n.at n=36A366317