A369768 Numbers X such that X^2 + Y^2 = 3^(2*k) + 1 and X > Y > 0 and k is the ternary digit length of X-1.

3, 9, 21, 27, 71, 81, 195, 233, 243, 711, 729, 1583, 1749, 2157, 2187, 6561, 14829, 15747, 19629, 19683, 57609, 59049, 141717, 154727, 175537, 177147, 385559, 394471, 414649, 422729, 446489, 462601, 468919, 482759, 488431, 504161, 515649, 524559, 529599, 530529

Offset: 1

Author

A.H.M. Smeets, Jan 31 2024

Keywords

• nonn
• base

Comments

The number of terms for a given k is A025435(3^(2*k)+1).

Links

• A.H.M. Smeets, Table of n, a(n) for n = 1..191

Crossrefs

Cf. A004018, A025435.

Cf. A369703 (base 2), this sequence (base 3), A369769 (base 5), A368418 (base 10).