On Thu, 18 Aug 2005, Eric Angelini wrote:
Could please someone compute and analyse this sequence?
Start with a(1) = 1 Describe a(1) --> = 11 (one "1") Add a(1) to it's description: 1 + 11 = 12 [and so on...]
I can't help with the analysis, and I doubt that anything as simple as what is found for the sequence of audioactive elements could be said - but I would be happy to be contradicted. However I can help with a quick perl script: #!/usr/bin/perl -l use strict; use warnings; use bigint; $_=1; { print my $o=$_; s/((\d)\2*)/(length $1).$2/ge; $_+=$o; <>, redo; } __END__ Output: 1 12 1124 212338 1211334656 1112213525496172 31221113152327355441607884 1311223113111543352330284851467051780698 111321221321133115142315123621344927293054493947386362638861942616 311312112211131221232115111412131115111213161211243740343033324425294734255535516245454370615560667973830274103732 1321131112212231131122111213122115311411121113311531121113111611122112452629253224272531563339232924322532242625512536355352484547475838465750368051618862646083796870789687941287275044 Michele -- Never attribute to malice that which can be adequately explained by stupidity - "Hanlon's Razor"