1,1
For c < 1247 none sequence starting from c except 247 itself reachs 247
S(1247)=2473 then E(1247) = 3742
S(3742)=7420 then E(3742) = 247 then (c,1) = 247 and (c,2) = 1247
Cf. A006577, A129121.
Sequence in context: A063356 A127349 A051153 this_sequence A001243 A048901 A065146
Adjacent sequences: A129130 A129131 A129132 this_sequence A129134 A129135 A129136
easy,nonn,uned
Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), May 25 2007
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