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 A052404 Numbers without 2 as a digit. 14
 0, 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 58, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 83, 84, 85, 86, 87, 88, 89 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES M. J. Halm, Word Weirdness, Mpossibilities 66 (Feb. 1998), p. 5. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 M. J. Halm, Games M. F. Hasler, Numbers avoiding certain digits, OEIS Wiki, Jan 12 2020. FORMULA If the offset were changed to 0: a(0) = 0, a(n+1) = f(a(n)+1,f(a(n)+1) where f(x,y) = if x<10 and x<>2 then y else if x mod 10 = 2 then f(y+1,y+1) else f(floor(x/10),y). - Reinhard Zumkeller, Mar 02 2008 a(n) = replace digits d > 1 by d + 1 in base-9 representation of n - 1. - Reinhard Zumkeller, Oct 07 2014 Sum_{k>1} 1/a(k) = A082831 = 19.257356... (Kempner series). - Bernard Schott, Jan 12 2020, edited by M. F. Hasler, Jan 14 2020 MAPLE a:= proc(n) local l, m; l, m:= 0, n-1;       while m>0 do l:= (d->         `if`(d<2, d, d+1))(irem(m, 9, 'm')), l       od; parse(cat(l))/10     end: seq(a(n), n=1..100);  # Alois P. Heinz, Aug 01 2016 MATHEMATICA ban2Q[n_]:=FreeQ[IntegerDigits[n], 2]==True; Select[Range[0, 89], ban2Q[#] &] (* Jayanta Basu, May 17 2013 *) Select[Range[0, 100], DigitCount[#, 10, 2]==0&] (* Harvey P. Dale, Apr 13 2015 *) PROG (MAGMA) [ n: n in [0..89] | not 2 in Intseq(n) ];  // Bruno Berselli, May 28 2011 (sh) seq 0 1000 | grep -v 2; # Joerg Arndt, May 29 2011 (Haskell) a052404 = f . subtract 1 where    f 0 = 0    f v = 10 * f w + if r > 1 then r + 1 else r  where (w, r) = divMod v 9 -- Reinhard Zumkeller, Oct 07 2014 (PARI) lista(nn, d=2) = {for (n=0, nn, if (!vecsearch(vecsort(digits(n), , 8), d), print1(n, ", ")); ); } \\ Michel Marcus, Feb 21 2015 (PARI) apply( {A052404(n)=fromdigits(apply(d->d+(d>1), digits(n-1, 9)))}, [1..99]) next_A052404(n, d=digits(n+=1))={for(i=1, #d, d[i]==2&&return((1+n\d=10^(#d-i))*d)); n} \\ least a(k) > n: if there's a digit 2 in n+1, replace the first occurrence by 3 and all following digits by 0. (A052404_vec(N)=vector(N, i, N=if(i>1, next_A052404(N))))(99) \\ first N terms select( {is_A052404(n)=!setsearch(Set(digits(n)), 2)}, [0..99]) (A052404_upto(N)=select( is_A052404, [0..N]))(99) \\ M. F. Hasler, Jan 11 2020 CROSSREFS Cf. A004177, A004721, A072809, A082831 (Kempner series). Cf. A052382 (without 0), A052383 (without 1), A052405 (without 3), A052406 (without 4), A052413 (without 5), A052414 (without 6), A052419 (without 7), A052421 (without 8), A007095 (without 9). See A038604 for the subset of primes. - M. F. Hasler, Jan 11 2020 Sequence in context: A026511 A321153 A304814 * A298112 A026417 A026421 Adjacent sequences:  A052401 A052402 A052403 * A052405 A052406 A052407 KEYWORD base,easy,nonn AUTHOR Henry Bottomley, Mar 13 2000 EXTENSIONS Offset changed by Reinhard Zumkeller, Oct 07 2014 STATUS approved

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Last modified June 21 11:31 EDT 2021. Contains 345363 sequences. (Running on oeis4.)