A368159 The n-th term in the trajectory of the n-th prime P under the 'Px+1' map.

2, 10, 13, 5, 336, 111, 19, 215, 1404, 537, 318, 19, 1, 1, 12, 19, 1, 41231, 103, 18, 1, 10, 42, 3120474, 32580, 17, 26, 351348, 260402, 38082, 128, 60457, 138, 140, 547278, 6869, 1, 164, 21, 87, 90, 16245, 12, 194, 33, 90645, 106, 224, 1, 230, 1, 60, 121, 1

Offset

1,1

Comments

See A057684 for definition.

Links

Paolo Xausa, Table of n, a(n) for n = 1..1000

Formula

a(n) = A368085(n,n).

Example

For n= 4: prime(4)  =  7 ->   50 ->  25 ->   5  = a(4).
For n= 5: prime(5)  = 11 ->  122 ->  61 -> 672 -> 336  = a(5).
For n= 6: prime(6)  = 13 ->  170 ->  85 ->  17 -> 222 -> 111  = a(6).
For n=13: prime(13) = 41 -> 1682 -> 841 ->  29 ->   1 ->  42 ->
                      21 ->    7 ->   1 ->  42 ->  21 ->   7 -> 1 = a(13).

Mathematica

Px1[p_, n_]:=Catch[For[i=1, i<PrimePi[p], i++, If[Divisible[n, Prime[i]], Throw[n/Prime[i]]]]; p*n+1];
A368159[n_]:=Nest[Px1[Prime[n], #]&, Prime[n], n-1];
Array[A368159, 100] (* Paolo Xausa, Dec 14 2023 *)

Crossrefs

Main diagonal of A368085.

Cf. A000040, A057684, A057689, A057690, A057691.

Sequence in context: A303356 A299317 A095914 * A189079 A045218 A177856

Adjacent sequences: A368156 A368157 A368158 * A368160 A368161 A368162

Keyword

nonn

Author

Alois P. Heinz, Dec 13 2023

Status

approved