A201544 Odd numbers of the form x^2 + 2*y^2 with positive integers x and y.

3, 9, 11, 17, 19, 27, 33, 41, 43, 51, 57, 59, 67, 73, 75, 81, 83, 89, 97, 99, 107, 113, 121, 123, 129, 131, 137, 139, 147, 153, 163, 171, 177, 179, 187, 193, 201, 209, 211, 219, 225, 227, 233, 241, 243, 249, 251, 257, 267, 275, 281, 283, 289, 291, 297, 307

Offset

1,1

Comments

All terms == {1,3} mod 8. Terms that are not multiple of some previous term are prime numbers (see A033203, except for the first term 2 there).

For the numbers with positive proper representations see A225771 without member 1, the subsequence without 75 = 3*5^2, 147 = 3*7^2, 225 = (3*5)^2, 275 = 5^2*11, ... - Wolfdieter Lang, Jan 14 2025

Links

Table of n, a(n) for n=1..56.

Crossrefs

Intersection of A005408 and A154777.

Cf. A033200 (primes), A033203, A225771.

Sequence in context: A047471 A354938 A365082 * A225771 A215816 A211864

Adjacent sequences: A201541 A201542 A201543 * A201545 A201546 A201547

Keyword

nonn

Author

Zak Seidov, Dec 02 2011

Status

approved