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A295124 a(n) = smallest number k with n prime factors such that 2d + k/d is prime for every d | k. 2
1, 3, 15, 105, 93081 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Such k must be an odd squarefree number.
a(n) has 2^n divisors and each gives another prime.
Conjecture: the sequence is infinite. It is hard to believe!
a(n) is the smallest k such that A088627(k) = A000005(k) = 2^n.
LINKS
FORMULA
a(n) = A293756(n+1)/2.
CROSSREFS
Subsequence of A244520 (2d + k/d is prime for every d|k).
Sequence in context: A231634 A353587 A128276 * A107878 A218688 A120016
KEYWORD
nonn,more
AUTHOR
Thomas Ordowski, Nov 15 2017
EXTENSIONS
a(4) from Michel Marcus, Nov 15 2017
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)