1,2

Table of n, a(n) for n=1..58.

20/4=5 is 1 mod 4 and so is 21, therefore 20 is in sequence.

Cf. A091072, A106841, A106837.

Contains A106841 and A106841+1.

Sequence in context: A004756 A237882 A153034 * A242663 A160053 A140612

Adjacent sequences: A106837 A106838 A106839 * A106841 A106842 A106843

nonn

Ralf Stephan, May 03 2005

approved