%I A117432
%S A117432 1,20,63,104
%N A117432 Let n be an integer consisting of m digits. Then n is a Phithy number 
               if the n-th m-tuple in the decimal digits of golden ratio phi is 
               string n.
%C A117432 The next such number is greater than 10^6.
%H A117432 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               GoldenRatio.html">The Golden Ratio</a>
%e A117432 1 is a term because the first single digit in golden ratio phi is 1.
%e A117432 Number 20 is a term because the 20th pair of digits in phi is 20.
%e A117432 (cf. phi = 1.6180339887498948482045868343656381177203...)
%t A117432 PhithyNumbers[m_] := Module[{cc = m(10^m)+m, sol, aa}, sol = Partition[RealDigits[GoldenRatio, 
               10, cc] // First, m]; Do[aa = FromDigits[sol[[i]]]; If[aa==i, Print[{i, 
               aa}]], {i,Length[sol]}];] Example: PhithyNumbers[3] produces all 
               3-digit Phithy numbers
%Y A117432 Cf. A001622, A109513, A109514, A117431.
%Y A117432 Sequence in context: A007248 A117431 A159504 this_sequence A033577 A074632 
               A158444
%Y A117432 Adjacent sequences: A117429 A117430 A117431 this_sequence A117433 A117434 
               A117435
%K A117432 base,more,nonn
%O A117432 0,2
%A A117432 Colin Rose (colin(AT)tri.org.au), Mar 14 2006