20081

Appears in sequences

• Composite numbers not divisible by 7 which in base 7 contain their largest proper factor as a substring.at n=5A063877
• Sum of next n composite numbers.at n=31A072475
• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 5 on top of a fixed block of the same size so that the building is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees.at n=9A123793
• Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 8 king-move adjacent elements, with upper left element zero.at n=13A305247
• Number of distinct row/column permutations of plane partitions of n.at n=10A321645
• Irregular triangle read by rows: the right-hand side of the triangle in A349815.at n=73A349816
• a(n) = 2^(2*n - HammingWeight(n)) * [x^n] ((1 - x)^(-5/2) - (x - 1)^(-2)).at n=7A380951