A380644 Numbers that can be expressed as 4*j*k+j+k, j,k >= 1, as well as 4*j*k-j-k, j,k >= 2.

26, 41, 47, 56, 61, 68, 71, 74, 86, 89, 96, 101, 107, 110, 116, 128, 131, 140, 146, 151, 152, 155, 159, 161, 166, 173, 176, 182, 185, 191, 194, 201, 206, 208, 209, 215, 221, 224, 236, 239, 242, 250, 251, 257, 261, 263, 266, 271, 272, 278, 281, 290, 293, 296, 299

Offset: 1

Author

Hugo Pfoertner, Jan 29 2025

Keywords

• nonn

Examples

			a(1) = 26, because 26 = 4*1*5 + 1 + 5 = 4*2*4 - 2 - 4.
a(2) = 41: 41 = 4*1*8 + 1 + 8 = 4*3*4 - 3 - 4.
		

Crossrefs

Cf. A054520, A124934, A125217, A125218, A380140, A380509, A380572.