A350193 Indices that give distinct values of A350090 in the order in which they appear.

0, 1, 5, 7, 22, 33, 124, 187, 757, 852, 876, 1149, 1541, 5951, 6767, 8454, 10067, 15555, 20272, 29751, 51721, 59662, 89055, 90088, 92489, 161673, 207737, 217341, 225622, 361054, 452639, 530990, 560684, 669999, 733454, 1000067, 1866828, 2090121, 2464677, 3148962

Offset: 1

Author

Michel Marcus, Dec 19 2021

Keywords

• nonn

Crossrefs

Cf. A002378, A003215, A350090, A350120, A350192.

Programs

Mathematica

With[{s = Table[Count[Range[0, n - 1], ?(IntegerQ@ Sqrt[4 # + 1] &[(3 n (n + 1) + 1) - (3 # (# + 1) + 1)] &)], {n, 0, 2^10}]}, Map[-1 + FirstPosition[s, #][[1]] &, DeleteDuplicates@ s]] (* _Michael De Vlieger, Dec 19 2021, after Amiram Eldar at A350090 *)

Extensions

a(1) = 0 inserted by and more terms from Jinyuan Wang, Dec 19 2021