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%I #13 Oct 09 2023 17:38:46
%S 1,27,125,1000,10648,103823,1000000,10077696,100544625,1000000000,
%T 10007873875,100026577288,1000000000000,10000909453625,
%U 100000721719296,1000000000000000,10000073940248384,100000075387171679,1000000000000000000,10000004316234262875
%N a(n) is the smallest n-digit cube.
%F a(n) = ceiling(10^((n-1)/3))^3. - Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
%e a(4) = 1000 = 10^3 has 4 digits while 9^3 = 729 has 3 digits.
%p A061434 := n->ceil(10^((n-1)/3))^3;
%t Table[Ceiling[Surd[10^n,3]]^3,{n,0,20}] (* _Harvey P. Dale_, Oct 09 2023 *)
%o (Python)
%o from sympy import integer_nthroot
%o def a(n):
%o r, exact = integer_nthroot(10**(n-1), 3)
%o return 10**(n-1) if exact else (r+1)**3
%o print([a(n) for n in range(1, 21)]) # _Michael S. Branicky_, Jan 27 2021
%o (PARI) a(n) = ceil(10^((n-1)/3))^3; \\ _Michel Marcus_, Jan 27 2021
%Y Cf. A000578, A061432, A061433.
%K nonn,base,easy
%O 1,2
%A _Amarnath Murthy_, May 03 2001
%E More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001
%E More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
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