42778

Appears in sequences

• Triangular numbers with sum of digits = 28.at n=8A068132
• Triangular numbers which are the sum of two squares.at n=39A073613
• Triangular numbers with palindromic indices.at n=38A089717
• Min{m: n = Sum((m mod (1+k*L(n)!))*2^(k-1): 1<=k<=L(n))}, where L(n) = length of binary representation of n, cf. A070939, A000142.at n=12A094096
• Primitive numbers in A229307.at n=29A229311
• Triangular numbers n with digits d_1, d_2, ..., d_k such that d_1*(d_1+1)/2 + ... + d_k*(d_k+1)/2 is a triangular number.at n=34A254957
• Number of length n 1..(2+2) arrays with no leading partial sum equal to a prime and no consecutive values equal.at n=17A255710
• Numbers n with the property that the symmetric representation of sigma(n) has four parts, each of width one and two regions meet at the center of the Dyck path.at n=19A264104
• Triangular numbers T(i) that can be expressed as the sum of 2 positive triangular numbers, T(j)+T(k), and for which i+j+k is a triangular number, where T is A000217.at n=4A343426
• Triangular numbers that in base 2 have the same number of 0's and 1's.at n=27A345348
• Number of semi-sums of integer partitions of n.at n=30A366738