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A271471 Values k > 1 in A271328 such that k does not have any nontrivial divisors in A271328. 1
5, 17, 28, 37, 82, 106, 122, 197, 228, 257, 294, 362, 406, 577, 628, 677, 842, 906, 1161, 1228, 1297, 1376, 1522, 1606, 1682, 1937, 2028, 2117, 2402, 2513, 2606, 2917, 3028, 3142, 3482, 3606, 3722, 4236, 4357, 4629, 4762, 4906, 5042, 5483, 5777, 6242, 6406 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If k is in this sequence, then all multiples of k are in A271468.

LINKS

Peter Kagey, Table of n, a(n) for n = 1..10000

EXAMPLE

A271328(1) = 1 is not in this sequence because A271328(1) is not greater than 1.

A271328(2) = 5 is in this sequence because 5 does not have any nontrivial divisors.

A271328(3) = 10 is not in this sequence because A271328(2) is a proper divisor of A271328(3).

A271328(4) = 17 is in this sequence because 17 does not have any nontrivial divisors.

A271328(5) = 28 is in this sequence because 2, 4, 7, and 14 are not in A271328.

MATHEMATICA

nn = 240; s = {1}; Do[AppendTo[s, Total@ Select[Range[n - 1], Divisible[n, s[[#]]] &]], {n, 2, nn}]; t = Table[s[[3 n]]/3, {n, nn/3}];

Select[Rest@ t, NoneTrue[Most@ Rest@ Divisors@ #, MemberQ[t, #] &] &] (* Michael De Vlieger, Apr 08 2016 *)

CROSSREFS

Sequence in context: A196142 A195032 A264618 * A217512 A289836 A068829

Adjacent sequences:  A271468 A271469 A271470 * A271472 A271473 A271474

KEYWORD

nonn

AUTHOR

Peter Kagey, Apr 08 2016

STATUS

approved

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Last modified May 21 10:48 EDT 2019. Contains 323443 sequences. (Running on oeis4.)