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%I #8 Mar 04 2019 01:31:54
%S 0,1,125,24389,343,17576,10648,29791,8,21952,54010152,941192,12812904,
%T 551368,531441,89915392,88716536,571787,421875,2197,512000,262144,
%U 1668222856,20123648,13824000,15625000,9261,27,34328125,61629875,343000
%N Smallest cube that contains the decimal digits of n in its exact middle.
%C "Exact" middle means that the counts of digits to the left and to the right of the digits of n in the cube are the same.
%e The elements a(15) to a(18) are 899//15//392 = 448^3, 887//16//536 = 446^3, 57//17//87 = 83^3 and 42//18//75 = 75^3, where double slashes show the position of the digits of n.
%p A163596 := proc(n) ndi := convert(n,base,10) ; lenndi := nops(ndi) ; for c from 0 do cdi := convert(c^3,base,10) ; lencdi := (nops(cdi)-lenndi)/2 ; if lencdi >=0 and type(lencdi,'integer') then if op(1+lencdi..lencdi+lenndi,cdi) = op(ndi) then RETURN(c^3) ; fi; fi; od: end:
%p for n from 1 to 30 do printf("%d,",A163596(n)) ; od: # _R. J. Mathar_, Aug 01 2009
%K nonn,base
%O 0,3
%A _Claudio Meller_, Aug 01 2009
%E Extended by _R. J. Mathar_, Aug 01 2009
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