20174

Appears in sequences

• Number of points on surface of hexagonal prism: 12*n^2 + 2 for n > 0 (coordination sequence for W(2)).at n=41A005914
• Coordination sequence for MgNi2, Position Ni1.at n=35A009933
• Numbers n such that x^n + x^5 + x^4 + x^3 + x^2 + x + 1 is irreducible over GF(2).at n=50A057484
• Number of ways to tile hexagon of edge n with diamonds of side 1, not counting rotations and reflections as different.at n=4A066931
• Final members of groups in A076105.at n=37A076102
• Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both semiprime.at n=32A085774
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 0), (-1, 0, 1), (0, -1, 1), (1, 1, 0)}.at n=9A149134
• a(n) = 1331*n - 1122.at n=15A157441
• Number of binary strings of length n with equal numbers of 00100 and 10001 substrings.at n=15A164240
• a(n) = Sum_{k=1..n} k*lcm(k,k')/gcd(k,k'), where k' is arithmetic derivative of k.at n=24A190122
• Number of n-digit 7th powers.at n=33A216657
• Least k such that A006577(k) = A006577(n) + A006577(n+1).at n=53A277962