21882

Appears in sequences

• Numbers k such that 39*2^k + 1 is prime.at n=45A002269
• Numbers k such that 297*2^k-1 is prime.at n=43A050907
• Integers x such that for some integer y we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).at n=11A067739
• Even numbers of the form floor( binomial(2k, 2j)/binomial(k, j)).at n=13A111304
• Number of ways of writing n as the sum of 7 triangular numbers.at n=46A226252
• Partial sums of A253090.at n=39A255603
• Numbers n such that Bernoulli number B_{n} has denominator 1806.at n=29A272139
• Number of nX4 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=6A279264
• Number of nX7 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=3A279267
• T(n,k)=Number of nXk 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=48A279268
• T(n,k)=Number of nXk 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=51A279268
• Number of ways to write n as an ordered sum of 6 prime power palindromes (A084092).at n=28A282845
• Number of nX5 0..1 arrays with every element unequal to 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=8A317860
• Number of permutations of length n whose powers all avoid the pattern 132.at n=15A326762
• Triangle read by rows: T(n,k) is the number of balanced reduced multisystems of weight n with atoms colored using exactly k colors.at n=22A330776
• Sum of number of divisors of x^y for each x >= 1, y >= 0, x + y = n.at n=45A343657
• Number of Aut(G)-orbits on G-characters that come from Riemann surfaces of genus n.at n=37A347373
• Expansion of e.g.f. 1/(1 - x^2 * exp(x)).at n=7A358080
• Expansion of e.g.f. A(x) satisfying A(x) = x + A( x^2*exp(x) ), with A(0) = 0.at n=6A369091