51000

Appears in sequences

• Aliquot sequence starting at 840 (reaches 1 at 747th term).at n=5A045477
• Numbers whose square has more than 2/3 of its digits the same.at n=32A060813
• Numbers n divisible by exactly three nontrivial permutations (rearrangements) of the digits of n.at n=6A090058
• Positive integers i for which A112049(i) == 9.at n=18A112069
• (n^4 - 10*n^2 + 15*n - 6)/2.at n=17A135916
• Positive integers n such that n^2 = (x^4 - y^4)*(z^4 - t^4) where the pairs of integers (x,y) and (z,t) are not proportional.at n=33A147854
• Number of reduced words of length n in Coxeter group on 6 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.at n=7A162743
• First differences of A175111.at n=5A175112
• Numbers with prime factorization p*q*r^3*s^3 (where p, q, r, s are distinct primes).at n=28A190108
• Molecular topological indices of the Moebius ladders.at n=24A192833
• Molecular topological indices of the prism graphs Y_n.at n=24A192838
• Number of (n+1)X(n+1) 0..3 arrays with the upper median of every 2X2 subblock equal.at n=1A237068
• Number of (n+1)X(2+1) 0..3 arrays with the upper median of every 2X2 subblock equal.at n=1A237070
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the upper median of every 2X2 subblock equal.at n=4A237076
• Numbers k such that 2*10^k + 93 is prime.at n=31A275523
• Numbers that are not palindromes even after removing trailing zeros and are divisible by their reverses.at n=22A345361
• Number of polygon edges formed when connecting all 4n points on the perimeter of an n X n square by infinite lines.at n=7A345650
• Infinitary aliquot sequence starting at 840: a(1) = 840, a(n) = A126168(a(n-1)), for n >= 2.at n=5A361421
• a(n) = sigma_1(n) * sigma_2(n).at n=23A379812