27593

Appears in sequences

• Numbers n such that 1n1, 3n3, 7n7 and 9n9 are all primes.at n=36A059677
• n*10^2-1, n*10^2-3, n*10^2-7 and n*10^2-9 are all prime.at n=33A064976
• 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, 0), (-1, 0, 0), (0, 0, -1), (0, 1, -1), (1, 0, 1)}.at n=9A149318
• (2^p-(p+2))/p as p runs through the primes.at n=7A164740
• Number of Lyndon words appearing as n-th degree terms in Baker-Campbell-Hausdorff series.at n=19A220587
• Number of relatively prime Lyndon compositions (aperiodic necklaces of positive integers) with sum n.at n=18A318731
• a(n) = numerator of Sum_{k=2..A335138(n)} abs(A309229(n, k))/k.at n=23A335416
• Odd composite integers m such that A052918(m-J(m,29)) == 0 (mod m) and gcd(m,29)=1, where J(m,29) is the Jacobi symbol.at n=35A340095
• Number of non-Look-and-Say partitions of n. Number of integer partitions of n such that there is no way to choose a disjoint strict integer partition of each multiplicity.at n=39A351293