Saturday, June 24, 2017

Number of the day: 7170

Properties of the number 7170:

7170 = 2 × 3 × 5 × 239 is the 6253th composite number and is squarefree.
7170 has 4 distinct prime factors, 16 divisors, 9 antidivisors and 1904 totatives.
7170 has an emirpimes digit sum 15 in base 10.
7170 has a triangular digit sum 15 in base 10.
7170 is the difference of 2 positive pentagonal numbers in 2 ways.
7170 = 52 + 162 + 832 is the sum of 3 positive squares.
71702 = 43022 + 57362 is the sum of 2 positive squares in 1 way.
71702 is the sum of 3 positive squares.
7170 is a proper divisor of 4792 - 1.
7170 is palindromic in (at least) the following bases: 14, 56, 67, -36, and -64.
7170 in base 7 = 26622 and consists of only the digits '2' and '6'.
7170 in base 14 = 2882 and consists of only the digits '2' and '8'.
7170 in base 25 = bbk and consists of only the digits 'b' and 'k'.
7170 in base 34 = 66u and consists of only the digits '6' and 'u'.
7170 in base 55 = 2KK and consists of only the digits '2' and 'K'.
7170 in base 56 = 2G2 and consists of only the digits '2' and 'G'.

The number 7170 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A054341: Row sums of triangle A054336 (central binomial convolutions).
A055574: n satisfying sigma(n+1) = sigma(n-1).
A067347: Square array read by antidiagonals: T(n,k)=(T(n,k-1)*n^2-Catalan(k-1)*n)/(n-1) with a(n,0)=1 and a(1,k)=Catalan(k) where Catalan(k)=C(2k,k)/(k+1)=A000108(k).
A076036: G.f.: 1/(1 - 5*x*C(x)), where C(x) = (1 - sqrt(1 - 4*x))/(2*x) = g.f. for the Catalan numbers A000108.
A125205: Triangular array T(n,k) (n>=1, 0<=k<=n(n-1)/2) giving the total number of connected components in all subgraphs (V,E') with |E'|=k of the complete labeled graph K_n=(V,E).
A125206: Triangular array T(n,k) (n>=1, 0<=k<=n(n-1)/2) giving the total number of connected components in all subgraphs obtained from the complete labeled graph K_n by removing k edges.
A139274: a(n) = n*(8*n-1).
A239832: Number of partitions of n having 1 more even part than odd, so that there is an ordering of parts for which the even and odd parts alternate and the first and last terms are even.
A240192: T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or three plus the sum of the elements diagonally to its northwest, modulo 4
A269467: T(n,k)=Number of length-n 0..k arrays with no repeated value equal to the previous repeated value.

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