A332531 Even numbers k such that A103230(k) is a perfect square.

442, 818, 1130, 1226, 1326, 1576, 2454, 3094, 3390, 3678, 3978, 4728, 4862, 5330, 5726, 5986, 6452, 7362, 7786, 7910, 8362, 8398, 8582, 8998, 9282, 10166, 10170, 10250, 11032, 11034, 11934, 12410, 12430, 13486, 13702, 14184, 14586, 15542, 15990, 17178, 17336

Offset

1,1

Comments

The odd numbers k such that A103230(k) is a perfect square are the numbers that are divisible only by primes congruent to 3 mod 4 (A004614).

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

442 is a term since A103230(442) = 2433600 = 1560^2.

Mathematica

Select[2 * Range[9000], IntegerQ @ Sqrt[Abs[DivisorSigma[1, #, GaussianIntegers -> True]]^2] &]

Crossrefs

Cf. A004614, A006532, A103230.

Sequence in context: A013769 A013899 A075268 * A158322 A031720 A069106

Adjacent sequences: A332528 A332529 A332530 * A332532 A332533 A332534

Keyword

nonn

Author

Amiram Eldar, Feb 15 2020

Status

approved