19276

Appears in sequences

• Numbers m such that 2*phi(m) = phi(m+1).at n=21A050472
• a(n) = Sum_{k=1..n} lcm(k,n)/gcd(k,n).at n=38A056789
• Numbers n with the property that n is an anagram of the digits of the distinct prime factors of n.at n=5A096595
• Recurrence derived from the decimal places of sqrt(2). a(0)=0, a(i+1)=position of first occurrence of a(i) in decimal places of sqrt(2).at n=12A098326
• Trajectory of 1001 under "3x+1" map.at n=19A100709
• 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, 0, 1), (0, 0, 1), (1, 0, 0), (1, 1, -1)}.at n=8A150135
• Numbers n, not divisible by 3, 5, 7 or 11, such that A000203(n)-n-1 and 2*n+1-A000203(n) are prime numbers.at n=8A180268
• Number of defective 3-colorings of an n X 5 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.at n=3A229531
• T(n,k) = number of defective 3-colorings of an n X k 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.at n=31A229534
• Number of defective 3-colorings of a 4 X n 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.at n=4A229537
• Number of nX4 0..1 arrays with every element equal to 0, 3, 4, 5, 7 or 8 king-move adjacent elements, with upper left element zero.at n=10A299577
• Numbers k such that sopfr(k) = tau(k)^2.at n=16A305026
• Composite numbers that are anagrams of the concatenation of their prime factors.at n=10A306474
• Column 1 of triangle A370041.at n=27A370154