20275

Appears in sequences

• a(n) = Sum_{k=0..floor(n/2)} T(n,k), T given by A026725.at n=14A026733
• Number of nX5 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=6A223946
• Number of 7 X n 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=4A223954
• Numbers k such that 7*R_(k+2) + 10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=19A257033
• Number of n X 3 0..1 arrays with the number of 1's king-move adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.at n=5A284108
• Number of n X 6 0..1 arrays with the number of 1's king-move adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.at n=2A284111
• T(n,k) = Number of n X k 0..1 arrays with the number of 1's king-move adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.at n=30A284113
• T(n,k) = Number of n X k 0..1 arrays with the number of 1's king-move adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.at n=33A284113
• For any nonnegative real number x, let f(x) be the real number obtained by replacing in the binary expansions of the integer and fractional parts of x each finite run of k consecutive equal bits b with a run of k-(-1)^k consecutive bits b; a(n) is the numerator of f(1/n).at n=36A323626
• Number of integer partitions of n with no part divisible by all the others.at n=37A343341
• a(n) is the smallest number which can be represented as the sum of n distinct perfect powers (A001597) in exactly n ways, or -1 if no such number exists.at n=45A363040