27129

Appears in sequences

• Numbers k such that 10*7^k + 1 is prime.at n=21A057437
• Numbers n such that n and prime(n) end with the same three digits.at n=24A067841
• Numbers whose square is a zeroless pandigital number (i.e., use the digits 1 through 9 once).at n=25A071519
• n+phi(n)+phi(phi(n)) is a cube.at n=21A116042
• 1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having one or three distinct clockwise edge differences.at n=3A210070
• 1/4 the number of (n+1)X5 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences.at n=0A210073
• T(n,k)=1/4 the number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences.at n=6A210077
• T(n,k)=1/4 the number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences.at n=9A210077
• Numbers whose square contains all of the digits 1 through 9.at n=25A294661
• Number of multiset partitions of uniform integer partitions of n in which all parts have the same length.at n=45A320451
• a(n) = Sum_{k=1..n} k^2 * floor(n/k)^3.at n=20A350124