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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 Ray Chandler, Table of n, a(n) for n = 1..10000 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 Cf. A074173, A308736. Sequence in context: A217588 A264339 A045942 * A096026 A278003 A308736 Adjacent sequences: A308732 A308733 A308734 * A308736 A308737 A308738 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.)