1,5

A124220(n) = A047969(n) - Trn(A0123685).

Row six of A047969 is 1 9 37 65 31 1

Row six of A123685^T is 0 7 14 46 15 1

so row six of a(n) is 1 2 23 19 16 0

The sequence of row sums is 0 1 2 6 18 61 224 ... = A123639. The sequence of row sums for table A123685 is 1 1 3 8 25 83 299 ... = A123638. The sequence of row sums for table A047969 is 1 2 5 14 43 144 523 ... = A047970

Cf. A047970 A123638 A123639.

Sequence in context: A097559 A123226 A102210 this_sequence A110298 A144740 A049501

Adjacent sequences: A124217 A124218 A124219 this_sequence A124221 A124222 A124223

easy,nonn,tabl

Alford Arnold (Alford1940(AT)aol.com), Oct 29 2006