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Numbers in A152022 which are not products of terms of A152021.
5

%I #7 Sep 01 2019 02:36:48

%S 65,260,273,325,1025,1029,1040,1045,1092,1105,1281,1300,1345,1365,

%T 4097,4100,4116,4160,4165,4180,4368,4420,4433,5124,5125,5185,5200,

%U 5380,5460,16385,16388,16400,16401,16405,16464,16465,16640,16645,16660,16705,16709,16720

%N Numbers in A152022 which are not products of terms of A152021.

%t f[n_] := FromDigits[IntegerDigits[n, 2], 4]; s = Array[f, 300, 2]; div[a_, b_] := Divisible[a, b] && a > b; n = 1; s0 = s; While[Length[s] > n, s = Select[s, ! div[#, s[[n]]] &]; n++]; s1 = Complement[s0, s]; aQ[n_, s_] := Times @@ (s^(IntegerExponent[n, #] & /@ s)) == n; Select[s1, ! aQ[#, s] &] (* _Amiram Eldar_, Aug 31 2019 *)

%Y Cf. A000695, A152021, A152022.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Nov 20 2008, Jun 11 2009

%E a(12)-a(14) inserted and more terms added by _Amiram Eldar_, Aug 31 2019

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Last modified September 20 13:10 EDT 2024. Contains 376072 sequences. (Running on oeis4.)