64090

Appears in sequences

• Numbers that are the sum of 2 nonzero squares in exactly 8 ways.at n=9A025291
• Numbers that are the sum of 2 nonzero squares in 7 or more ways.at n=9A025298
• Numbers that are the sum of 2 nonzero squares in 8 or more ways.at n=9A025299
• Numbers that are the sum of 2 distinct nonzero squares in exactly 8 ways.at n=9A025309
• Numbers that are the sum of 2 distinct nonzero squares in 7 or more ways.at n=9A025317
• Numbers that are the sum of 2 distinct nonzero squares in 8 or more ways.at n=9A025318
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 56.at n=1A031644
• 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=18A066290
• Numbers k that are the hypotenuse of exactly 40 distinct integer-sided right triangles, i.e., k^2 can be written as a sum of two squares in 40 ways.at n=4A097282
• a(n) = 4394*n - 1820.at n=14A156627
• Number of ways that a 1 X n rectangular tile T, marked into n unit squares, can be surrounded by one layer of copies of itself laid in the plane grid generated by the units of T. Ways that differ by rotation or reflection are not counted as different. The surrounded tile is the exact surrounded region.at n=24A159294
• Partial products of A002313, the primes that are 1 or 2 (mod 4).at n=4A185952
• 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=19A229996
• Factored over the Gaussian integers, the least positive number having n prime factors, including units -1, i, and -i.at n=9A239629
• Numbers such that A017666(n) = A017668(n).at n=6A261989
• Expansion of Sum_{p prime, i>=2} x^(p^i)/(1 - x^(p^i)) / Product_{j>=1} (1 - x^j).at n=40A281611
• Expansion of Product_{k>=1} 1 / (1 - Sum_{j>=1} j * x^(k*j)).at n=12A329156
• Primitive integers for the number of ways k to write as a sum of two squares.at n=34A336542
• Numbers k with Goldbach partitions (p,q) and (r,s) such that k | (p*q -1) and k | (r*s +1).at n=8A336584
• Numbers k such that the sum of the squares of the odd divisors of k (A050999) is divisible by k.at n=23A355543