A350315 Length of the rows of the Redstone permutation A350313.

2, 3, 6, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 12, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 12, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4, 6, 6, 6, 8, 4

Offset

1,1

Comments

See the comments and the example section of A350313 for definitions.

Links

Table of n, a(n) for n=1..86.

Formula

Apparently for n >= 4: a(n) = 2 * b(n - 4) + 6, where the generating function of b(n) is (-3*x^33 + x^29 - x^28 + x^24 - x^23 + x^19 - x^18 + x^14 - x^13 + x^9 - x^8 + x^4 - x^3)/(x^34 - 1).

Mathematica

s = {2, 1}; c[_] = 0; Array[Set[c[s[[#]]], #] &, Length[s]]; j = Last[s]; u = 3; Prepend[Differences[#], First[#]] &[{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, 500}], i]][[-1, -1]]] (* Michael De Vlieger, Dec 24 2021 *)

Crossrefs

Cf. A350313, A350314.

Sequence in context: A151850 A290223 A274213 * A078706 A077082 A333936

Adjacent sequences: A350312 A350313 A350314 * A350316 A350317 A350318

Keyword

nonn

Author

Peter Luschny, Dec 24 2021

Status

approved