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 A052419 Numbers without 7 as a digit. 14
 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 80, 81, 82, 83, 84, 85, 86, 88, 89 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 M. F. Hasler, Numbers avoiding certain digits OEIS wiki, Jan 12 2020. FORMULA a(n) = replace digits d > 6 by d + 1 in base-9 representation of n - 1. - Reinhard Zumkeller, Oct 07 2014 Sum_{n>1} 1/a(n) = A082836 = 22.493475... (Kempner series). - Bernard Schott, Jan 12 2020, edited by M. F. Hasler, Jan 13 2020 MAPLE a:= proc(n) local l, m; l, m:= 0, n-1;       while m>0 do l:= (d->         `if`(d<7, 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 Select[Range[100], DigitCount[#, 10, 7]==0&] (* Harvey P. Dale, Aug 23 2011 *) PROG (MAGMA) [ n: n in [0..89] | not 7 in Intseq(n) ]; // Bruno Berselli, May 28 2011 (sh) seq 0 1000 | grep -v 7; # Joerg Arndt, May 29 2011 (Haskell) a052419 = f . subtract 1 where f 0 = 0 f v = 10 * f w + if r > 6 then r + 1 else r where (w, r) = divMod v 9 -- Reinhard Zumkeller, Oct 07 2014 (PARI) lista(nn)=for (n=0, nn, if (!vecsearch(vecsort(digits(n), , 8), 7), print1(n, ", ")); ); \\ Michel Marcus, Feb 22 2015 (PARI) /* See OEIS wiki page for more programs. */ apply( {A052419(n)=fromdigits(apply(d->d+(d>6), digits(n-1, 9)))}, [1..99]) \\ a(n) select( {is_A052419(n)=!setsearch(Set(digits(n)), 7)}, [0..99]) \\ used in A038615 next_A052419(n, d=digits(n+=1))={for(i=1, #d, d[i]==7&&return((1+n\d=10^(#d-i))*d)); n} \\ least a(k) > n. Used in A038615. - M. F. Hasler, Jan 11 2020 CROSSREFS Cf. A004182, A004726, A038615 (subset of primes), A082836 (Kempner series). Cf. A052382 (without 0), A052383 (without 1), A052404 (without 2), A052405 (without 3), A052406 (without 4), A052413 (without 5), A052414 (without 6), A052421 (without 8), A007095 (without 9). Sequence in context: A038673 A183219 A049533 * A257458 A179439 A047421 Adjacent sequences:  A052416 A052417 A052418 * A052420 A052421 A052422 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 May 12 19:15 EDT 2021. Contains 343829 sequences. (Running on oeis4.)