Sunday, May 21, 2017

Number of the day: 4820

Properties of the number 4820:

4820 = 22 × 5 × 241 is the 4170th composite number and is not squarefree.
4820 has 3 distinct prime factors, 12 divisors, 23 antidivisors and 1920 totatives.
4820 has a semiprime digit sum 14 in base 10.
4820 = 12062 - 12042 = 2462 - 2362 is the difference of 2 nonnegative squares in 2 ways.
4820 is the difference of 2 positive pentagonal numbers in 2 ways.
4820 = 462 + 522 = 142 + 682 is the sum of 2 positive squares in 2 ways.
4820 = 182 + 202 + 642 is the sum of 3 positive squares.
48202 = 24002 + 41802 = 5882 + 47842 = 19042 + 44282 = 28922 + 38562 is the sum of 2 positive squares in 4 ways.
48202 is the sum of 3 positive squares.
4820 is a proper divisor of 6594 - 1.
4820 is palindromic in (at least) the following bases: 18, 19, 61, -21, -29, -66, and -79.
4820 in base 18 = efe and consists of only the digits 'e' and 'f'.
4820 in base 19 = d6d and consists of only the digits '6' and 'd'.
4820 in base 24 = 88k and consists of only the digits '8' and 'k'.
4820 in base 28 = 644 and consists of only the digits '4' and '6'.
4820 in base 60 = 1KK and consists of only the digits '1' and 'K'.
4820 in base 61 = 1I1 and consists of only the digits '1' and 'I'.

The number 4820 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A000899: Number of solutions to the rook problem on an n X n board having a certain symmetry group (see Robinson for details).
A005969: Sum of fourth powers of Fibonacci numbers.
A008608: Number of n X n upper triangular matrices A of nonnegative integers such that a_1i + a_2i + ... + a_{i-1,i} - a_ii - a_{i,i+1} - ... - a_in = -1.
A052447: Number of simple 2-edge-connected unlabeled n-node graphs.
A063867: Number of solutions to +- 1 +- 2 +- 3 +- ... +- n = 0 or +- 1.
A129991: Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+241)^2 = y^2.
A164770: Numbers n with property that average digit of n^2 is 2.
A235098: T(n,k)=Number of (n+1)X(k+1) 0..5 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant stress tilted 1X1 tilings)
A265058: Coordination sequence for (2,3,8) tiling of hyperbolic plane.
A266650: Expansion of Product_{k>=1} (1 + x^k - x^(3*k)) / (1 - x^k).

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