login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A123724 as a simple table

na(n)
1-1
20
3-1
4-2
5-1
6-2
7-1
80
9-1
100
11-1
12-2
13-1
14-2
15-1
160
17-1
180
19-1
20-2
21-1
22-2
23-1
240
25-1
260
271
280
291
300
31-1
320
33-1
340
351
360
371
380
39-1
400
41-1
420
431
440
451
460
47-1
480
49-1
500
511
520
531
542
551
562
571
580
591
600
611
622
631
642
651
660
671
680
691
702
711
722
731
740
751
760
77-1
780
79-1
800
811
820
831
840
85-1
860
87-1
880
891
900
911
920
93-1
940
95-1
960
971
980
991
1000

[-1,0,-1,-2,-1,-2,-1,0,-1,0,-1,-2,-1,-2,-1,0,-1,0,
 -1,-2,-1,-2,-1,0,-1,0,1,0,1,0,-1,0,-1,0,1,0,1,0,
 -1,0,-1,0,1,0,1,0,-1,0,-1,0,1,0,1,2,1,2,1,0,1,0,1,
 2,1,2,1,0,1,0,1,2,1,2,1,0,1,0,-1,0,-1,0,1,0,1,0,
 -1,0,-1,0,1,0,1,0,-1,0,-1,0,1,0,1,0]