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%I #8 Sep 08 2022 08:46:19
%S 1,4,11,14,22,28,41,44,82,88,111,114,122,128,141,144,182,188,212,218,
%T 221,224,242,248,281,284,411,414,422,428,441,444,482,488,812,818,821,
%U 824,842,848,881,884,1111,1114,1122,1128,1141,1144,1182,1188,1212,1218
%N Numbers n such that product of digits of n is a power of 4.
%C Supersequence of A032822.
%e 1111 is in the sequence because 1*1*1*1 = 1 = 4^0.
%t FromDigits /@ Select[Join @@ Map[Tuples[2^Range[0, 3], #] &, Range@ 4], IntegerQ@ Log[4, Times @@ #] &] (* _Michael De Vlieger_, Mar 25 2017 *)
%o (Magma) Set(Sort([n: n in [1..10000], k in [0..20] | &*Intseq(n) eq 4^k]))
%Y Cf. Numbers n such that product of digits of n is a power of k for k = 0 - 9: A284375 (k = 0), A002275 (k = 1), A028846 (k = 2), A174813 (k = 3), this sequence (k = 4), A276037 (k = 5), A276038 (k = 6), A276039 (k = 7), A284324 (k = 8), A284295 (k = 9).
%K nonn,base
%O 0,2
%A _Jaroslav Krizek_, Mar 25 2017
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