A257572 Prime root of n-th term in A257278.

2, 2, 2, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 5, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 5, 2, 3, 7, 2, 3, 5, 2, 2, 3, 7, 2, 5, 3, 2, 2, 7, 3, 5, 2, 3, 2, 5, 2, 7, 3, 2, 2, 3, 5, 7, 2, 3, 2, 5, 2, 3, 7, 2, 5, 3, 2, 2, 3, 7, 2, 5, 2, 3, 11, 2, 7, 5, 3, 2, 2, 3

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n) = A020639(A257278(n)).

A257278(n) = a(n) ^ A257573(n).

a(n) <= A257573(n) by definition of A257278.

Mathematica

seq[lim_] := Module[{s = {}, p = 2, r}, While[p^p <= lim, r = Range[p, Log[p, lim]]; AppendTo[s, Transpose[{ConstantArray[p, Length[r]], p^r}]]; p = NextPrime[p]]; SortBy[Flatten[s, 1], Last][[;; , 1]]]; seq[10^13] (* Amiram Eldar, Apr 14 2025 *)

Prog

(Haskell)
a257572 = a020639 . a257278

Crossrefs

Cf. A257278, A020639, A025473, A257573.

Sequence in context: A346651 A085694 A258570 * A160493 A053760 A223942

Adjacent sequences: A257569 A257570 A257571 * A257573 A257574 A257575

Keyword

nonn

Author

Reinhard Zumkeller, May 01 2015

Status

approved