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A308735 Numbers k such that k, k+2, k+4 are of the form p^2*q where p and q are distinct primes. 3
2523, 2525, 3175, 22021, 25529, 28223, 40325, 53573, 58923, 73447, 122571, 132021, 149675, 152339, 165175, 172917, 202221, 209673, 235825, 267773, 268223, 308671, 322223, 371075, 425723, 430171, 445923, 488975, 575973, 591575 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
All terms are odd. See comment in A308736. - Chai Wah Wu, Jun 24 2019
LINKS
EXAMPLE
3175 = 5 * 5 * 127,
3177 = 3 * 3 * 353,
3179 = 11 * 17 * 17.
MATHEMATICA
psx = Table[{0}, {5}]; nmax = 600000; n = 1; lst = {};
While[n < nmax, n++;
psx = RotateRight[psx];
psx[[1]] = Sort[Last /@ FactorInteger[n]];
If[Union[{psx[[1]], psx[[3]], psx[[5]]}] == {{1, 2}},
AppendTo[lst, n - 4]]; ];
lst
CROSSREFS
Sequence in context: A217588 A264339 A045942 * A096026 A278003 A308736
KEYWORD
nonn
AUTHOR
Ray Chandler, Jun 24 2019
STATUS
approved

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Last modified February 21 07:26 EST 2024. Contains 370219 sequences. (Running on oeis4.)