A080810 - OEIS

%I #10 Aug 07 2015 03:14:44

%S 7,576,17576,1475789056,1420778345789277056227207,

%T 149247077443060991182553045537892735703095362592472033442634721

%N a(1) = 7, a(n)= smallest n-th power obtained by inserting digits anywhere in a(n-1).

%e 24^2=576. 26^3=17576. 196^4=1475789056. 67687^5=1420778345789277056227207.

%p buffedStr := proc(n,candid) local f ; if length(n) = 0 then RETURN(true) ; fi ; f := SearchText(substring(n,1),candid) ; if f = 0 then RETURN(false) ; else if buffedStr(substring(n,2..-1),substring(candid,f+1..-1)) = true then RETURN(true) ; else RETURN(false) ; fi ; fi ; end: A080810 := proc(preva,n) local i,tst ; i := 1 ; while true do tst := i^n ; if buffedStr(convert(preva,string),convert(tst,string)) = true then RETURN(tst) ; fi ; i := i+1 ; od: end: an :=7 ; for n from 2 to 15 do an := A080810(an,n) ; end ; # _R. J. Mathar_, Sep 20 2006

%Y Cf. A080804, A080805, A080806, A080807, A080808, A080809, A080811, A080812.

%K base,more,nonn

%O 1,1

%A _Amarnath Murthy_, Mar 22 2003

%E Corrected and extended by _R. J. Mathar_, Sep 20 2006

%E One more term. _Sean A. Irvine_, Sep 01 2009