OFFSET
1,4
LINKS
Peter Kagey, Table of n, a(n) for n = 1..10011 (first 141 antidiagonals, flattened)
EXAMPLE
Addition table begins:
+ | 0 1 3 7 12 20 30 44 65
-----+-----------------------------
0 | 0 1 3 7 12 20 30 44 65
1 | 1 2 4 8 13 21 31 45 66
3 | 3 4 6 10 15 23 33 47 68
7 | 7 8 10 14 19 27 37 51 72
12 | 12 13 15 19 24 32 42 56 77
20 | 20 21 23 27 32 40 50 64 85
30 | 30 31 33 37 42 50 60 74 95
44 | 44 45 47 51 56 64 74 88 109
65 | 65 66 68 72 77 85 95 109 130
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Peter Kagey, Oct 07 2020
STATUS
approved