A350314 The catch-up points of the Redstone permutation A350313.

2, 5, 11, 17, 23, 29, 37, 41, 47, 53, 59, 67, 71, 77, 83, 89, 97, 101, 107, 113, 119, 127, 131, 137, 143, 149, 157, 161, 167, 173, 179, 187, 191, 197, 203, 209, 221, 227, 233, 239, 247, 251, 257, 263, 269, 277, 281, 287, 293, 299, 307, 311, 317, 323, 329, 337

Offset: 1

Author

Peter Luschny, Dec 24 2021

Keywords

• nonn

Comments

We say n is a 'catch-up point' of a permutation p of the positive integers if and only if p restricted to [n] = {1, 2, ..., n} is a permutation of [n].

The periodic structure of the first differences is described in A350315.

Crossrefs

Cf. A350313, A350315.

Programs

Mathematica

s = {2, 1}; c[] = 0; Array[Set[c[s[[#]]], #] &, Length[s]]; j = Last[s]; u = 3; {2}~Join~Reap[Monitor[Do[If[j == u, While[c[u] > 0, u++]]; k = u; While[Nand[c[k] == 0, CoprimeQ[i, k], ! Divisible[i - 1, k]], k++]; If[k == u, Sow[i]]; Set[c[k], i]; j = k, {i, Length[s] + 1, 337}], i]][[-1, -1]] (* _Michael De Vlieger, Dec 24 2021 *)