OFFSET
1,2
COMMENTS
The square array A(row,col) is read by descending antidiagonals: A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), etc.
LINKS
FORMULA
EXAMPLE
The top left {1..9} x {1..18} corner of the array:
1, 2, 6, 24, 120, 720, 5040, 40320, 362880
3, 8, 30, 144, 840, 5760, 45360, 403200, 3991680
4, 12, 48, 240, 1440, 10080, 80640, 725760, 7257600
5, 14, 54, 264, 1560, 10800, 85680, 766080, 7620480
7, 26, 126, 744, 5160, 41040, 367920, 3669120, 40279680
9, 32, 150, 864, 5880, 46080, 408240, 4032000, 43908480
10, 36, 168, 960, 6480, 50400, 443520, 4354560, 47174400
11, 38, 174, 984, 6600, 51120, 448560, 4394880, 47537280
13, 50, 246, 1464, 10200, 81360, 730800, 7297920, 80196480
15, 56, 270, 1584, 10920, 86400, 771120, 7660800, 83825280
16, 60, 288, 1680, 11520, 90720, 806400, 7983360, 87091200
17, 62, 294, 1704, 11640, 91440, 811440, 8023680, 87454080
18, 72, 360, 2160, 15120, 120960, 1088640, 10886400, 119750400
19, 74, 366, 2184, 15240, 121680, 1093680, 10926720, 120113280
20, 78, 384, 2280, 15840, 126000, 1128960, 11249280, 123379200
21, 80, 390, 2304, 15960, 126720, 1134000, 11289600, 123742080
22, 84, 408, 2400, 16560, 131040, 1169280, 11612160, 127008000
23, 86, 414, 2424, 16680, 131760, 1174320, 11652480, 127370880
PROG
CROSSREFS
Inverse permutation: A276956.
Transpose: A276953.
Cf. A153880.
The following lists some of the rows that have their own entries. Pattern present in the factorial base expansion of the terms on that row is given in double quotes:
Row 1: A000142 (from a(1)=1, "1" onward),
Row 2: A001048 (from a(2)=3, "11" onward),
Row 3: A052849 (from a(2)=4, "20" onward).
Row 4: A052649 (from a(1)=5, "21" onward).
Row 5: A108217 (from a(3)=7, "101" onward).
Row 6: A054119 (from a(3)=9, "111" onward).
Row 7: A052572 (from a(2)=10, "120" onward).
Row 8: A001344 (from a(1)=11, "121" onward).
Row 13: A052560 (from a(3)=18, "300" onward).
Row 16: A225658 (from a(1)=21, "311" onward).
Row 20: A276940 (from a(3) = 27, "1011" onward).
KEYWORD
AUTHOR
Antti Karttunen, Sep 22 2016
STATUS
approved