34836

Appears in sequences

• Number of cycles induced by iterating the Gray-coding of an n-bit number: a(n+1) = a(n) + 2^n/C_n, where C_n = least power of 2 >= n (C_n is the length of the cycle), with a(0) = 1.at n=20A007886
• Least number k such that k*p(n)*(k*p(n)+1)-1, k*p(n)*(k*p(n)+1)+1, k*p(n)*(k*p(n)+3)-1 and k*p(n)*(k*p(n)+3)+1 are all primes, two pairs of twin primes, with p(i) = i-th prime.at n=45A139638
• Number of permutations of [n] with a fixed point and/or a succession.at n=8A207819
• a(1)=2; for n > 1, a(n) = 2^(n-2) + (1/(2n-2)) * Sum_{ d divides n-1 } phi(2d)*2^((n-1)/d).at n=16A216957
• Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=5A300806
• Number of nX6 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=2A300809
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=30A300811
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=33A300811
• a(n) is the number of 4 element sets of distinct integer sided strict rectangles that fill an n X n square.at n=41A384724