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(0=0, 1=1, 2=2, 3=3, 4=2^2, 5=5, 6=2*3, 7=7, 8=2^3, 9=3^2, 10=2*5, 11=11, 12=2^2*3, ..) becomes (0*(0+1), 1*(2+2), 3*(3+4), 2*(2+5), 5*(6+2), 3*(7+7), 8*(2+3), 9*(3+2), 10*(2+5), 11*(11+12), 2*(2+3), ..).
0

%I #5 Mar 30 2012 18:52:27

%S 0,4,21,14,40,42,40,45,70,253,10,351,44,63,42,340,63,418,52,87,68,598,

%T 84,140,80,93,18,1711,16,1953,76,135,104,215,10,148,798,624,200,410,

%U 210,602,176,528,102,140,2350,208,364,14,1020,208,1378,270,180,638,192,231

%N (0=0, 1=1, 2=2, 3=3, 4=2^2, 5=5, 6=2*3, 7=7, 8=2^3, 9=3^2, 10=2*5, 11=11, 12=2^2*3, ..) becomes (0*(0+1), 1*(2+2), 3*(3+4), 2*(2+5), 5*(6+2), 3*(7+7), 8*(2+3), 9*(3+2), 10*(2+5), 11*(11+12), 2*(2+3), ..).

%e 13*(13+14)=351=a(12).

%e 2*(7+15)=44=a(13).

%e 3*(5+16)=63=a(14).

%e 2*(4+17)=42=a(15).

%e 17*(18+2)=340=a(16).

%e 3*(2+19)=63=a(17).

%e 19*(20+2)=418=a(18).

%e 2*(5+21)=210=a(19),

%e etc.

%Y Cf. A002808.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Dec 01 2008

%E Corrected (210 replaced by 52, 506 by 68, 72 by 76 etc.) by _R. J. Mathar_, May 01 2010