1,3
7337 is in the sequence because (1) it is an icosagonal number and (2) the sum of the digits 7+3+3+7=20 is also an icosagonal number.
Cf. A051872.
Sequence in context: A031799 A116248 A140078 this_sequence A097696 A128478 A043589
Adjacent sequences: A117796 A117797 A117798 this_sequence A117800 A117801 A117802
nonn,base
Luc Stevens (lms022(AT)yahoo.com), Apr 29 2006
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