215496

Appears in sequences

• Smith triangular numbers.at n=22A098840
• Number of 4-indecomposable (connected) graphs on n nodes.at n=30A128526
• Smallest triangular number whose decimal expansion ends (nontrivially) with the n-th triangular number.at n=30A229262
• Triangular numbers which have one or more occurrences of exactly six different digits.at n=29A241789
• Square array A(1,k) = A265907(k), A(n>1,k) = A(n-1, k+1) - A(n-1, k); successive differences of A265907 read by descending antidiagonals as A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ...at n=24A275960
• Transpose of array A275960.at n=24A275961
• G.f. = Phi^2*F^4, where Phi = g.f. for A028930, F = g.f. for A028959.at n=22A328535
• Triangular numbers such that the three numbers before it and the three numbers after it are squarefree.at n=17A374393