67100670

Appears in sequences

• Number of Barlow packings with group P6(bar)m2 that repeat after 2n layers.at n=27A011949
• Number of aperiodic binary strings of length n; also number of binary sequences with primitive period n.at n=26A027375
• Nextprime(4^n)-nextprime(2^n).at n=13A037130
• Row sums of triangle T(m,n) = number of solutions to 1 <= a(1) < a(2) < ... < a(m) <= n, where gcd(a(1), a(2), ..., a(m), n) = 1, in A020921.at n=25A038199
• Number of primitive (aperiodic) words of length n which contain exactly two different symbols.at n=25A056267
• Number of triangles similar to their n-th pedal, and not similar to any k-th pedal for k < n.at n=12A102536
• a(n) = 4^n-2^n-2.at n=12A170940
• Number of similarity classes of vectors with minimal Ducci period n.at n=27A269795
• Sum of 2^k for residue k in among Lucas numbers mod n.at n=25A336685
• Numbers k such that A246601(k) > 2*k.at n=19A359084