31855

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 25 ones.at n=17A031793
• Numbers k such that k-th and (k+1)-st term of A038593 differ by 3.at n=24A038634
• Numbers k such that the smoothly undulating palindromic number(18*10^k - 81)/99 is a prime.at n=10A062214
• a(n) gives the odd leg of one of the two Pythagorean triangles with hypotenuse A080109(n) = A002144(n)^2. This is the smaller of the two possible odd legs.at n=26A253802
• Number of Motzkin trees that are "uniquely closable skeletons".at n=22A300126
• a(n) = n^4 - 3*n^3 + 9*n^2 - 7*n + 5 (n>=1).at n=13A304162
• a(n) is the sum of all products of pairs of numbers joined by the diagonals of an n-gon when its vertices are numbered from 1 to n in order.at n=22A337130