55556

Appears in sequences

• Kaprekar triples: q such that q = x + y + z and q^3 = x*10^2n + y*10^n + z, where z < 10^n and n is the number of digits in q. q is not a power of 10 (except q=1).at n=15A006887
• Numbers having four 5's in base 10.at n=25A043512
• Find smallest pair (x,y) such that x^2 - y^2 = 11...1 (n times) = (10^n-1)/9; sequence gives value of x.at n=9A048611
• a(n) = a(n-1)+a(m), where m=2n-2-2^(p+1) and 2^p<n-1<=2^(p+1), for n >= 4.at n=34A050071
• Index numbers for palindromic hexagonal numbers.at n=16A054970
• Pseudo-Kaprekar triples: q such that if q=x+y+z, then q^3=x*10^i + y*10^j + z, where (y*10^j+z < 10^i) and z < 10^j.at n=28A060768
• Erroneous version of A006887.at n=16A060809
• a(n) = sqrt(A084004(n)).at n=14A084005
• a(n) = (n*10^n - n + 9)/9.at n=5A091693
• Expansion of g.f. (1-5*x)/((1-x)*(1-10*x)).at n=5A093142
• Records in A068189 (smallest number k such that n = product of nonzero digits of k, or 0 if no such k exists).at n=51A096867
• Numbers A such that the square of concatenation AA is of form NNMM.at n=14A107677
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having three, four or five distinct values for every i,j,k<=n.at n=16A211570
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|=|y-z|+1.at n=34A212680
• For k in {2,3,...,9} define a sequence as follows: a(0)=0; for n>=0, a(n+1)=a(n)+1, unless a(n) ends in k, in which case a(n+1) is obtained by replacing the last digit of a(n) with the digit(s) of k^2. This is k(7).at n=42A237344
• Sequence has property that when divided into chunks by cutting it before each digit '1', each chunk contains exactly one 1, two 2's, three 3's, ..., and nine 9's. See Comments for more detailed definition.at n=53A245628
• Numbers which have only digits 5 and 6 in base 10.at n=31A256291
• Numbers k where k^2 is an anagram of (k+2)^2.at n=20A261749
• Numbers of the form N = a+b+c such that N^3 = concat(a,b,c); a, b, c > 0.at n=11A328198
• Numbers k >= 1 such that k^2 - r^2 is a repunit (A002275) for some 1 <= r < k.at n=25A389493