55250

Appears in sequences

• Numbers that are the sum of 2 nonzero squares in exactly 8 ways.at n=5A025291
• Numbers that are the sum of 2 nonzero squares in 7 or more ways.at n=5A025298
• Numbers that are the sum of 2 nonzero squares in 8 or more ways.at n=5A025299
• Numbers that are the sum of 2 distinct nonzero squares in exactly 8 ways.at n=5A025309
• Numbers that are the sum of 2 distinct nonzero squares in 7 or more ways.at n=5A025317
• Numbers that are the sum of 2 distinct nonzero squares in 8 or more ways.at n=5A025318
• Numbers k such that the sum of the squares of the divisors of k is divisible by k.at n=38A046762
• Numbers m such that DivisorSigma(4*k-2, m) mod m = 0 holds presumably for all k; that is, (4k-2)-power-sums of divisors of m are divisible by m for all k.at n=17A066290
• Number of partitions of n into distinct partition numbers.at n=31A068006
• Expansion of (1+x^2*C^2)*C^3, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=9A071722
• a(1) = 1. For n > 1, a(n) = a(n-1) if n is prime, a(n) = a(n-1)/n if n is composite and divides a(n-1) else a(n) = n*a(n-1).at n=34A088304
• Numbers n that are the hypotenuse of exactly 31 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 31 ways.at n=2A097244
• a(n) = A139480(n)/2.at n=27A139481
• Number of simple labeled graphs on n+2 nodes with exactly n connected components that are trees or cycles.at n=24A215862
• Numbers which are the sum of two squared primes in exactly four ways (ignoring order).at n=15A226599
• For every positive integer m, let u(m) = (d(1),d(2),...,d(k)) be the unitary divisors of m. The sequence (a(n)) consists of successive numbers m which d(k)/d(1) + d(k-1)/d(2) + ... + d(k)/d(1) is an integer.at n=18A229996
• a(n) = 5*(3*n+1)*(9*n+8)/2 (n>=0).at n=28A304508
• Primitive integers for the number of ways k to write as a sum of two squares.at n=33A336542
• Partition the integers from 1 to n into three groups with consecutive numbers, then a(n) is the maximum value of the sum of the numbers in the second group multiplied by the minimum of the sum of the numbers in the first and third groups.at n=33A342713
• The smallest number k that can be partitioned in n ways as the sum of two numbers from A020487.at n=20A369384