31212

Appears in sequences

• Numbers n such that n / product of digits of n is a square.at n=22A001104
• Number of Twopins positions.at n=25A005690
• n written in fractional base 5/3.at n=37A024633
• Numerators of continued fraction convergents to sqrt(767).at n=11A042478
• Positive numbers n such that n is a multiple of (product of digits of n) * (sum of digits of n).at n=18A049102
• Consider the Diophantine equation x^3 + y^3 = z^3 - 1 (x < y < z) or 'Fermat near misses'. Arrange solutions by increasing values of z. Sequence gives values of x.at n=27A050788
• Consider the Diophantine equation x^3 + y^3 = z^3 - 1 (x < y < z) or 'Fermat near misses'. The values of z (see A050787) are arranged in monotonically increasing order. Sequence gives values of y.at n=24A050789
• Smallest composite which when sum of prime factors is repeatedly subtracted reaches a prime after n iterations.at n=38A053093
• T(2n,n), array T as in A054126.at n=6A054131
• Numbers divisible by the sum of factorials of their digits [A061602(n)] and also terminate in the sum of factorials of their digits.at n=23A071064
• Numbers k such that both the k-th and (k+1)-th primes have the same sum of digits squared but different sets of digits.at n=15A109183
• Integers corresponding to rational knots in Conway's enumeration.at n=41A122495
• Numbers that are multiples of their digital product, where this digital product also appears as their least significant digits.at n=29A167620
• Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, down, up, down.at n=2A177666
• Number of ways to place 2 nonattacking amazons (superqueens) on an n X n toroidal board.at n=16A178972
• Numbers of the form p^3*q^2*r^2 where p, q, and r are distinct primes.at n=15A179695
• Area A of the triangles such that A, the sides and three perpendicular bisectors are integers.at n=32A182171
• Numbers m such that the set of distinct prime divisors of m is equal to the set of distinct prime divisors of the arithmetic derivative m'.at n=30A201009
• Smallest integer m > n such that both n*m and (n+1)*(m+1) are squares.at n=12A212651
• G.f.: Sum_{n>=1} x^n * (1-x^n)^(n-1) / (1-x)^(n-1).at n=16A221834