A213084 Numbers consisting of ones and eights.

1, 8, 11, 18, 81, 88, 111, 118, 181, 188, 811, 818, 881, 888, 1111, 1118, 1181, 1188, 1811, 1818, 1881, 1888, 8111, 8118, 8181, 8188, 8811, 8818, 8881, 8888, 11111, 11118, 11181, 11188, 11811, 11818, 11881, 11888, 18111, 18118, 18181, 18188, 18811, 18818

Offset

1,2

Comments

One and eight begin with vowels. The subsequence of primes begins 11, 181, 811, 1181, 1811, 8111. - Jonathan Vos Post, Jun 14 2012

Links

Table of n, a(n) for n=1..44.

Mathematica

Flatten[Table[FromDigits/@Tuples[{1, 8}, n], {n, 5}]] (* Harvey P. Dale, Aug 27 2014 *)

Prog

(Python)
res = []
i = 0
while len (res) < 260:
    for c in str(i):
        if c in '18':
            continue
        else:
            break
    else:
        res.append(i)
    i = i + 1
print(res)
(PARI) is(n) = #setintersect(vecsort(digits(n), , 8), [0, 2, 3, 4, 5, 6, 7, 9])==0 \\ Felix Fröhlich, Sep 09 2019

Crossrefs

Cf. A020456 (primes in this sequence).

Cf. numbers consisting of 1s and ks: A007088 (k=0), A007931 (k=2), A032917 (k=3), A032822 (k=4), A276037 (k=5), A284293 (k=6), A276039 (k=7), A284294 (k=9).

Sequence in context: A318079 A000852 A000873 * A243520 A129730 A347757

Adjacent sequences: A213081 A213082 A213083 * A213085 A213086 A213087

Keyword

nonn,base,dumb,easy,word

Author

Jens Ahlström, Jun 05 2012

Status

approved