A166403 - OEIS

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A166403

Terms of sequence A166401 that are not powers of primes.

18, 36, 50, 75, 98, 100, 144, 147, 162, 196, 200, 225, 242, 245, 324, 338, 363, 392, 400, 441, 484, 507, 576, 578, 605, 676, 722, 784, 845, 847, 867, 882, 900, 968, 1058, 1083, 1089, 1156, 1183, 1225, 1250, 1296, 1352, 1444, 1445, 1458, 1521, 1587, 1600, 1682

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OFFSET

1,1

COMMENTS

Sequence A166401 contains the powers of the primes in addition to this sequence's terms. For those terms of A166401 that are composite, see A166402.

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[2, 1700], ! PrimePowerQ[#] && Divisible[(d = Divisors[#])[[n = Floor[Length[d]/2 + 1]]], d[[-n]]] &] (* Ivan Neretin, Jan 12 2016 *)

CROSSREFS

Cf. A166401, A166402

Sequence in context: A375397 A109428 A329611 * A004941 A004961 A008600