A180985 Array T(n,k) = number of n X k binary matrices with rows and columns in lexicographically nondecreasing order.
2, 3, 3, 4, 7, 4, 5, 14, 14, 5, 6, 25, 45, 25, 6, 7, 41, 130, 130, 41, 7, 8, 63, 336, 650, 336, 63, 8, 9, 92, 785, 2942, 2942, 785, 92, 9, 10, 129, 1682, 11819, 24520, 11819, 1682, 129, 10, 11, 175, 3351, 42305, 183010, 183010, 42305, 3351, 175, 11, 12, 231, 6280, 136564
Offset: 1
Examples
Table starts: ..2...3.....4.......5.........6...........7.............8................9 ..3...7....14......25........41..........63............92..............129 ..4..14....45.....130.......336.........785..........1682.............3351 ..5..25...130.....650......2942.......11819.........42305...........136564 ..6..41...336....2942.....24520......183010.......1202234..........6979061 ..7..63...785...11819....183010.....2625117......33345183........371484319 ..8..92..1682...42305...1202234....33345183.....836488618......18470742266 ..9.129..3351..136564...6979061...371484319...18470742266.....818230288201 .10.175..6280..402910..36211867..3651371519..358194085968...31887670171373 .11.231.11176.1099694.170079565.32017940222.6148026957098.1096628939510047 . All solutions for 3 X 3: ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 ..0..0..0....0..0..0....0..0..1....0..0..1....0..0..1....0..1..1....0..0..0 ..0..0..1....0..1..1....0..1..0....0..0..1....0..1..1....0..1..1....1..1..1 . ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..1 ..0..0..1....0..1..1....0..0..1....0..1..1....0..1..1....0..1..0....0..1..0 ..1..1..0....1..0..0....1..1..1....1..0..1....1..1..1....0..1..0....0..1..1 . ..0..0..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1 ..0..0..1....0..0..1....0..0..1....0..1..1....0..1..0....0..1..0....0..1..0 ..0..1..0....0..0..1....0..1..1....0..1..1....1..0..0....1..1..0....1..0..1 . ..0..0..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1 ..0..1..0....0..0..1....0..1..1....0..1..1....0..0..1....0..1..1....0..1..1 ..1..1..1....1..1..0....1..0..0....1..1..0....1..1..1....1..0..1....1..1..1 . ..0..0..0....0..0..1....0..0..1....0..0..1....0..1..1....0..1..1....0..1..1 ..1..1..1....1..1..0....1..1..0....1..1..1....0..1..1....0..1..1....0..1..1 ..1..1..1....1..1..0....1..1..1....1..1..1....0..1..1....1..0..0....1..0..1 ... ..0..1..1....0..1..1....0..1..1....0..1..1....0..1..1....0..1..1....0..1..1 ..0..1..1....1..0..0....1..0..0....1..0..0....1..0..1....1..0..1....1..0..1 ..1..1..1....1..0..0....1..0..1....1..1..1....1..1..0....1..0..1....1..1..1 . ..0..1..1....1..1..1 ..1..1..1....1..1..1 ..1..1..1....1..1..1
Links
Crossrefs
Programs
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PARI
A180985(h,w,cnt=0)={ local(A=matrix(h,w), z(r,c)=!while(r
1 && z(r,c), c--); while(c>1, A[r,c--]=0); while(r>1, A[r--,]=A[r+1,]); next(3))); break); cnt} \\ M. F. Hasler, Apr 27 2022
Formula
T(n,k) = T(k,n). T(1,k) = k+1. T(2,k) = A004006(k+1). T(3,k) = A184138(k). - M. F. Hasler, Apr 27 2022
Comments