A226470 a(n) = n^2 XOR triangular(n), where XOR is the bitwise logical exclusive-or operator.

0, 0, 7, 15, 26, 22, 49, 45, 100, 124, 83, 59, 222, 242, 173, 153, 392, 440, 495, 471, 322, 350, 281, 773, 876, 820, 1019, 931, 646, 762, 597, 561, 1552, 1648, 1751, 1727, 1930, 2022, 1857, 1789, 1396, 1484, 1379, 1163, 1102, 994, 3197, 3273, 3480, 3496, 3391, 3847, 4082

Offset: 0

Author

Alex Ratushnyak, Jun 08 2013

Keywords

• nonn
• base

Examples

			a(2) = 2^2 xor 2*3/2 = 4 xor 3 = 7.
		

Crossrefs

Cf. A000290, A000217.

Programs

Mathematica

Table[BitXor[n^2,(n(n+1))/2],{n,0,60}] (* Harvey P. Dale, Aug 11 2017 *)

Python

for n in range(99):
    print((n*n) ^ (n*(n+1)//2), end=", ")

Formula

a(n) = A000290(n) XOR A000217(n).