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a(n) is the minimal digit, expressed in base 10, in the base-n representation of 2^n.
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%I #15 Jan 18 2022 19:51:59

%S 0,2,0,1,1,2,0,2,0,1,2,2,4,8,0,1,1,0,1,8,4,1,2,2,4,2,4,1,1,0,0,6,3,0,

%T 17,1,2,0,6,2,3,1,1,2,0,2,0,1,2,8,1,2,4,7,1,4,3,1,1,0,2,8,0,5,3,1,2,1,

%U 4,0,1,2,4,1,2,3,5,1,2,19,4,1,1,3,4,5,7,1,2

%N a(n) is the minimal digit, expressed in base 10, in the base-n representation of 2^n.

%H Alois P. Heinz, <a href="/A350658/b350658.txt">Table of n, a(n) for n = 2..10000</a>

%p a:= n-> min(convert(2^n, base, n)):

%p seq(a(n), n=2..90); # _Alois P. Heinz_, Jan 10 2022

%t a[n_] := Min[IntegerDigits[2^n, n]]; Array[a, 100, 2] (* _Amiram Eldar_, Jan 10 2022 *)

%o (PARI) for(n=2,90,print1(vecmin(digits(2^n,n)),", "))

%o (Python)

%o from sympy.ntheory.digits import digits

%o def a(n): return min(digits(2**n, n)[1:])

%o print([a(n) for n in range(2, 91)]) # _Michael S. Branicky_, Jan 10 2022

%Y Cf. A350659.

%K nonn,base

%O 2,2

%A _Hugo Pfoertner_, Jan 10 2022