21474

Appears in sequences

• Number of n-celled polyominoes with holes.at n=12A001419
• Coordination sequence for MgNi2, Position Ni3.at n=36A009934
• Expansion of phi(x) / f(-x) in powers of x where phi(), f() are Ramanujan theta functions.at n=30A029552
• Number of positive integers <= 2^n of form 4 x^2 + 9 y^2.at n=18A054173
• Numbers which are the sum of their proper divisors containing the digit 7.at n=27A059466
• Records in A109734.at n=18A109739
• Sixth derivative of f_n at x=1, where f_n is the n-th of all functions that are representable as x^x^...^x with m>=1 x's and parentheses inserted in all possible ways.at n=29A215836
• Triangle T(n,k) in which n-th row lists the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).at n=29A216349
• Triangle T(n,k) in which n-th row lists in increasing order the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).at n=28A216350
• 2^n+1 appears in A109732 at position a(n).at n=10A261414
• Exponential convolution of number of partitions (A000041) and number of partitions into distinct parts (A000009).at n=10A307754
• One fourth of the number of permutations of [n] with |p(i+1) - p(i)| >= 2, for i = 1..(n-1) and n appears at position i = 1 or i = n.at n=5A384561