A031994 Duplicate of A023751.
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21, 22, 23, 24, 25, 26, 30, 31, 32, 33, 34, 35, 40, 41, 42, 43
Offset: 1
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
Sequence includes, respectively, 9, 16, 32, and 11 terms that are 1-, 2-, 3-, and 4- digit terms in both bases, and the following: a(69) = 14777 = 22238_9 a(70) = 15677 = 23448_9 a(71) = 22234 = 33444_9 a(72) = 22235 = 33445_9 a(73) = 22236 = 33446_9 a(74) = 22237 = 33447_9 a(75) = 22238 = 33448_9 a(76) = 22244 = 33455_9 a(77) = 22245 = 33456_9 a(78) = 22246 = 33457_9 a(79) = 22247 = 33458_9 a(80) = 22255 = 33467_9 a(81) = 22256 = 33468_9 a(82) = 22335 = 33566_9 a(83) = 22336 = 33567_9 a(84) = 22337 = 33568_9 a(85) = 22345 = 33577_9 a(86) = 22346 = 33578_9 a(87) = 22355 = 33588_9 a(88) = 44468 = 66888_9 a(89) = 222344 = 367888_9 a(90) = 1233467 = 2278888_9 a(91) = 12555566 = 25555888_9
filter:= proc(n) local L; L:= convert(n,base,10); `and`(seq(L[i+1]<=L[i],i=1..nops(L)-1)) end proc: ND[1]:= [$1..8]: R:= $0..8: for d from 2 to 10 do ND[d]:= map(t -> seq(9*t+r, r=(t mod 9) ..8), ND[d-1]); R:= R, op(select(filter, ND[d])); od: R; # Robert Israel, Nov 20 2019
Select[Range[0,1200],Min[Differences[IntegerDigits[#]]]>-1&& Min[ Differences[ IntegerDigits[ #,9]]]>-1&] (* Harvey P. Dale, Oct 14 2022 *)
Sequence includes 8 terms that are 1-digit numbers in both bases, 12 that are 2-digit numbers in both bases, 23 that are 3-digit terms in both bases, and the following: a(44) = 822 = 1466_8 = 1113_9 a(45) = 823 = 1467_8 = 1114_9 a(46) = 831 = 1477_8 = 1123_9 a(47) = 951 = 1667_8 = 1266_9 a(48) = 1023 = 1777_8 = 1356_9 a(49) = 10023 = 23447_8 = 14666_9 a(50) = 14774 = 34666_8 = 22235_9 a(51) = 14775 = 34667_8 = 22236_9 a(52) = 14783 = 34677_8 = 22245_9 a(53) = 599551 = 2222777_8 = 1113377_9 a(54) = 608623 = 2244557_8 = 1126777_9 a(55) = 1203126 = 4455666_8 = 2233336_9 a(56) = 1203127 = 4455667_8 = 2233337_9 a(57) = 1203135 = 4455677_8 = 2233346_9
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