31122

Appears in sequences

• T(2n+1,n+2), T given by A026758.at n=7A026877
• Numbers k such that (1/k) * Sum_{d|k} d*sigma(d) is an integer.at n=13A069520
• Least common multiple of numbers obtained by adding one to the odd divisors of n and subtracting 1 from the even divisors of n.at n=39A086536
• Integers corresponding to rational knots in Conway's enumeration.at n=42A122495
• Multiples of 1729, the Hardy-Ramanujan number.at n=18A138129
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, 1), (-1, 0), (0, 1), (1, -1)}.at n=11A151259
• Numbers k such that 64*k^6 + 1091 is prime.at n=31A155809
• Minimal covering numbers.at n=23A160559
• Number of monomer-dimer tatami tilings (no four tiles meet) of the n X n grid with n monomers and equal numbers of vertical and horizontal dimers, up to rotational symmetry.at n=19A182107
• Smallest possible largest number in a set of n integers such that sum of two elements is always a perfect square.at n=3A195854
• a(n) = (n+1)*(n-2)*(n-3)/2.at n=39A212343
• a(n) = A182107(4n+1).at n=4A226301
• Volume of right regular hexagonal pyramid with height and side lengths n, rounded down.at n=32A234729
• "Inside numbers". Pick a term "t" and one of its digits "d". Now jump to the right over d digits if "d" is odd, and to the left over d digits if "d" is even. Whatever the "d" you choose, you will stay on "t".at n=36A284515
• a(n) is the smallest k such that A319447(k) = n.at n=10A323020
• Positive integers that have a record number of divisors in Eisenstein integers.at n=30A323392
• a(n) = Sum_{1 <= m <= n} Sum_{1 <= k <= n+1-m} m*R(k,n+1), where R(k,b) = (b^k - 1)/(b - 1) is the base-b repunit of length k.at n=6A332082
• Table read by antidiagonals: T(w,n) is the number of n-step self avoiding walks on a 3D cubic lattice confined inside a tube of cross section w x w where the walk starts at the tube's edge.at n=37A337403
• Primitive terms of A051487.at n=20A346694
• Smallest exclusionary square (A029783) with exactly n distinct prime factors.at n=4A360301