A248204 Middle values in trios of products of 5 distinct primes.

16467034, 18185870, 21134554, 21374354, 21871366, 22247554, 22412534, 22721586, 24845314, 25118094, 25228930, 25435334, 25596934, 26217246, 27140114, 29218630, 29752346, 30323734, 30563246, 31943066, 32663266, 33367894, 36055046, 38269022, 39738062, 40547066

Offset

1,1

Comments

A subsequence of A066509 and offset by 1 from A192203.

Links

James G. Merickel, Table of n, a(n) for n = 1..26

Formula

a(n) = A192203(n) + 1.

Example

16467033=3*11*17*149*197,
16467034=2*19*23*83*227, and
16467035=5*13*37*41*167,
with no smaller similar trio. So a(1)=16467034. [Corrected by James G. Merickel, Jul 23 2015]

Prog

(PARI)
{
\\ This program checks all consecutives with elements not divisible \\
\\ by the squares of 2 or 3. More efficiency is required if enormous \\
\\ numbers of terms are sought and for the analog sequences beyond \\
\\ 6 prime factors. The start value is A093550(5). If a start other \\
\\ than this is chosen, one must be sure that (one of) s or u is \\
\\ adjusted if it needs to be. \\
n=16467034; s=[8, 4, 4, 4, 8, 8]; u=1;
while(1,
  if(issquarefree(n) && issquarefree(n-1) && issquarefree(n+1) && omega(n)==5 && omega(n-1)==5 && omega(n+1)==5, print1(n" "));
  n+=s[u];
  if(u==6, u=1, u++)
)
} \\ James G. Merickel, Jul 23 2015

Crossrefs

Cf. A066509, A192203, A248201, A248202, A248203, A259349, A259350, A259801.

Sequence in context: A155949 A355095 A192203 * A365812 A178555 A255164

Adjacent sequences: A248201 A248202 A248203 * A248205 A248206 A248207

Keyword

nonn

Author

James G. Merickel, Oct 28 2014

Status

approved