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URL: https://oeis.org/A190358

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A190358
Least number having exactly two odd prime factors that differ by 2^n.
2
15, 21, 33, 57, 185, 201, 393, 1841, 5753, 7217, 10265, 12297, 139553, 607577, 98313, 196617, 3801929, 786441, 27790073, 7340081, 35651873, 281022857, 92274809, 721422137, 1375733393, 6509569217, 3892314953, 805306377
OFFSET
1,1
LINKS
EXAMPLE
a(5) = 185 because 185 = 5 * 37 , and 37 - 5 = 32 = 2^5.
MATHEMATICA
f[n_] := Block[{p = 3}, While[! PrimeQ[p] || ! PrimeQ[p + 2^n], p++]; p (p + 2^n)]; Table[f[n], {n, 1, 60}]
CROSSREFS
Cf. A190052.
Sequence in context: A179996 A079814 A168354 * A090999 A123912 A346812
KEYWORD
nonn
AUTHOR
Michel Lagneau, May 09 2011
STATUS
approved