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A248204 Middle values in trios of products of 5 distinct primes. 8
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 (list; graph; refs; listen; history; text; internal format)
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: A216004 A155949 A192203 * A178555 A255164 A330247

Adjacent sequences:  A248201 A248202 A248203 * A248205 A248206 A248207

KEYWORD

nonn

AUTHOR

James G. Merickel, Oct 28 2014

STATUS

approved

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Last modified April 21 19:16 EDT 2021. Contains 343156 sequences. (Running on oeis4.)