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”).

A089680 as a simple table

na(n)
13
23
31
42
54
63
73
81
92
102
113
124
134
142
152
163
174
184
194
203
212
223
233
243
253
263
272
282
292
303
314
323
333
343
353
363
373
383
393
403
413
423
433
443
452
463
474
484
493
503
513
523
533
543
553
563
572
582
592
602
613
623
633
643
652
663
673
683
693
703
713
723
734
744
753
763
773
783
793
803
813
823
834
843
853
863
873
883
893
903
913
923
933
943
953
963
973
983
993
1003
1014
1024
1034
1044
1053

[3,3,1,2,4,3,3,1,2,2,3,4,4,2,2,3,4,4,4,3,2,3,3,3,
 3,3,2,2,2,3,4,3,3,3,3,3,3,3,3,3,3,3,3,3,2,3,4,4,3,
 3,3,3,3,3,3,3,2,2,2,2,3,3,3,3,2,3,3,3,3,3,3,3,4,4,
 3,3,3,3,3,3,3,3,4,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
 3,4,4,4,4,3]