71631
domain: N
Appears in sequences
- Doubly triangular numbers: a(n) = n*(n+1)*(n^2+n+2)/8.at n=27A002817
- Crystal ball sequence for A_4 lattice.at n=12A008384
- Integer part of the area of circles with prime radii.at n=35A097427
- Triangular numbers that are repdigits with length > 2 in some base.at n=27A274084
- Triangular numbers t(n) such that n / (product of decimal digits of t(n)) is an integer.at n=5A307792
- "Primitive" numbers k such that k divides 4^k - 1.at n=29A323203
- a(n) = A108625(n, 3*n).at n=4A363870