A329897 Numbers k for which the 2-adic and 3-adic valuations of A025487(k) are equal, where A025487(k) is the k-th number which is a product of primorial numbers.

1, 4, 9, 11, 20, 22, 23, 38, 41, 43, 44, 54, 69, 72, 73, 77, 79, 93, 110, 114, 118, 123, 124, 128, 129, 131, 147, 154, 181, 186, 190, 191, 199, 201, 208, 209, 212, 232, 242, 245, 246, 272, 279, 286, 294, 299, 300, 307, 310, 312, 321, 324, 327, 345, 359, 371, 374, 376, 416, 424, 425, 430, 434, 442, 446, 451, 454, 466, 469

Offset: 1

Author

Antti Karttunen, Dec 24 2019

Keywords

• nonn

Comments

Numbers k for which A007814(A025487(k)) = A007949(A025487(k)).

Numbers k for which A181815(k) is odd.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..7806

Crossrefs

Cf. A007814, A007949, A025487, A329898 (complement), A330682 (characteristic function).

Sequence A330683 sorted into ascending order.

Positions of odd terms in A181815.

Programs

Mathematica

s = {1}; k = 1; Do[If[GreaterEqual @@ (f = FactorInteger[n])[[;; , 2]] && PrimePi[f[[-1, 1]]] == Length[f], k++; If[Equal @@ IntegerExponent[n, {2, 3}], AppendTo[s, k]]], {n, 2, 10^5}]; s (* Amiram Eldar, Jul 28 2023 *)