A309065 Numbers n such that A014574(n) can be represented as a product of two terms in A014574.

8, 10, 13, 17, 23, 27, 33, 41, 52, 57, 64, 74, 94, 101, 108, 125, 126, 131, 148, 151, 158, 169, 171, 190, 193, 202, 206, 213, 225, 230, 240, 248, 252, 275, 292, 325, 345, 354, 355, 364, 412, 417, 430, 433, 437, 439, 444, 463, 484, 485, 486, 533, 542, 543, 557, 558, 580, 594

Offset

1,1

Links

Table of n, a(n) for n=1..58.

Formula

A307758(n) = A014574(a(n)).

Example

A014574(8) = 72 = 4 * 18. 4 and 18 are both in A014574, so a(1) = 8.
A014574(10) = 108 = 6 * 18. 6 and 18 are both in A014574, so a(2) = 10.
A014574(13) = 180 = 6 * 30. 6 and 30 are both in A014574, so a(3) = 13.

Mathematica

divQ[s_, n_] := AnyTrue[s, MemberQ[s, #] && MemberQ[s, n/#] &]; tpmidQ[n_]:= AllTrue[n + {-1, 1}, PrimeQ]; s={}; ind={}; c=0; Do[If[tpmidQ[n], c++; If[divQ[s, n], AppendTo[ind, c]]; AppendTo[s, n]], {n, 1, 10^5}]; ind (* Amiram Eldar, Jul 11 2019 *)

Crossrefs

Cf. A014574, A307758.

Sequence in context: A010916 A275627 A101764 * A048591 A102615 A308874

Adjacent sequences: A309062 A309063 A309064 * A309066 A309067 A309068

Keyword

nonn

Author

Dmitry Kamenetsky, Jul 10 2019

Extensions

More terms from Jinyuan Wang, Jul 11 2019

Status

approved