A353069 Positions k such that A097465(k) and A097465(k+1) are odd.

1, 2, 7, 12, 41, 100, 521, 1150, 10391, 15008, 255247, 1786778, 4849835, 5870858, 6561553, 557732162, 3234846601, 3457939474, 4360010651

Offset: 1

Author

Michael De Vlieger, May 05 2022

Keywords

• nonn
• more

Comments

Fixed points in A097465 appear in the intervals [12, 41], [100, 521], [1150, 10391], etc.

Links

• Rémy Sigrist, C program

Crossrefs

Cf. A097465, A351646, A352096.

Programs

C

See Links section.

Mathematica

nn = 2^20; c = {1}; j = 1; u = 2; {1}~Join~Reap[Do[k = u; While[Nand[FreeQ[c, k], CoprimeQ[j, k], k != j + 1, k != j - 1], k++]; j = k; AppendTo[c, k]; If[# != s, s = #; Sow[i - 1]] &@ Mod[#, 2] &@ Abs[k - i]; If[k == u, While[MemberQ[c, u], u++]; c = DeleteCases[c, _?(# < u &)]], {i, 2, nn}]][[-1, -1]]

Extensions

a(17)-a(19) from Rémy Sigrist, May 07 2022