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 A047739 Economical palindromes. 0
 343, 1331, 10201, 14641, 31213, 94249, 1030301, 1332331, 1367631, 1478741, 2060602, 2513152, 2551552, 2570752, 2939392, 2977792, 3090903, 3498943, 3637363, 3735373, 3850583, 5221225, 5265625, 5734375, 6948496, 11288211, 11333311, 12100121, 12499421, 13577531, 14655641, 22666622, 27700772, 29399392, 31244213, 33999933, 38988983, 58344385, 71111117, 100020001, 100585001, 101000101, 104060401, 104555401, 106878601 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE 343 = 7^3; 3 digits in 343, 2 digits in 7^3, so 343 is economical. MATHEMATICA d[n_]:=IntegerDigits[n]; palQ[n_]:=Reverse[(x=d[n])]==x; ecQ[n_]:=Length[Flatten[d[{First/@(x=FactorInteger[n]), DeleteCases[Last/@x, 1]}]]] < Length[d[n]]; t={}; Do[If[palQ[n] && ecQ[n], AppendTo[t, n]], {n, 3860000}]; t (* Jayanta Basu, May 16 2013 *) CROSSREFS Cf. A046759. Sequence in context: A117689 A178374 A179147 * A052084 A075546 A167733 Adjacent sequences:  A047736 A047737 A047738 * A047740 A047741 A047742 KEYWORD nonn,base AUTHOR EXTENSIONS a(11)-a(45) from Donovan Johnson, Nov 24 2010 STATUS approved

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Last modified April 22 14:41 EDT 2021. Contains 343177 sequences. (Running on oeis4.)