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Search: id:A038808
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%I A038808
%S A038808 0,7,919,999,25352,27872,31213,37973,45054,53135,54845,56765,60606,62426,
%T A038808 63936,74347,75357,78687,86868,90909,98289,121121,757757,982289,999999,
%U A038808 1063601,1081801,1188811,1197911,1366631,1393931,1507051,1644461
%N A038808 Palindromic numbers which are the difference of two positive cubes.
%t A038808 NextPalindrome[n_] := Block[ {l = Floor[ Log[10, n] + 1], idn = IntegerDigits[n]}, 
               If[ Union[ idn] == {9}, Return[n + 2], If[l < 2, Return[n + 1], If[ 
               FromDigits[ Reverse[ Take[ idn, Ceiling[l/2]]]] > FromDigits[ Take[ 
               idn, -Ceiling[l/2]]], FromDigits[ Join[ Take[ idn, Ceiling[l/2]], 
               Reverse[ Take[ idn, Floor[l/2]]]]], idfhn = FromDigits[ Take[ idn, 
               Ceiling[l/2]]] + 1; idp = FromDigits[ Join[ IntegerDigits[ idfhn], 
               Drop[ Reverse[ IntegerDigits[ idfhn]], Mod[l, 2]]]]]]]]; t1 = NestList[ 
               NextPalindrome, 0, 2800]; t2 = Select[ Union[Flatten[Table[n^3 - 
               m^3, {n, 900}, {m, n - 1}]]], # < 2*10^6 &]; Intersection[t1, t2] 
               - Robert G. Wilson v (rgwv(AT)rgwv.com)
%Y A038808 Cf. A002113, A038593, A109879.
%Y A038808 Sequence in context: A087350 A093171 A127102 this_sequence A068728 A028990 
               A151579
%Y A038808 Adjacent sequences: A038805 A038806 A038807 this_sequence A038809 A038810 
               A038811
%K A038808 nonn
%O A038808 1,2
%A A038808 Jeff Burch (gburch(AT)erols.com)
%E A038808 More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 14 2005

    
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Last modified December 21 10:15 EST 2009. Contains 171081 sequences.


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