A114478 Triangle read by rows; n-th row begins with n and contains n nonprimes greater than n and not already used.
0, 1, 4, 2, 6, 8, 3, 9, 10, 12, 4, 14, 15, 16, 18, 5, 20, 21, 22, 24, 25, 6, 26, 27, 28, 30, 32, 33, 7, 34, 35, 36, 38, 39, 40, 42, 8, 44, 45, 46, 48, 49, 50, 51, 52, 9, 54, 55, 56, 57, 58, 60, 62, 63, 64, 10, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77
Offset: 0
Examples
Triangle begins: 0; 1, 4; 2, 6, 8; 3, 9, 10, 12; 4, 14, 15, 16, 18; 5, 20, 21, 22, 24, 25;
Crossrefs
Cf. A113167.
Extensions
More terms from Sean A. Irvine, Sep 22 2011
a(0)=0 inserted by Michel Marcus, Feb 03 2023