A011537 Numbers that contain at least one 7.

7, 17, 27, 37, 47, 57, 67, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 87, 97, 107, 117, 127, 137, 147, 157, 167, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 187, 197, 207, 217, 227, 237, 247, 257, 267, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 287

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• base
• easy

Comments

Subsequence of primes is A257668. - Bernard Schott, Jul 21 2021

Links

• Muniru A Asiru, Table of n, a(n) for n = 1..5000
• Index entries for 10-automatic sequences.

Crossrefs

Complement of A052419.

Cf. A257668.

Programs

GAP

Filtered([1..280],n->7 in ListOfDigits(n)); # Muniru A Asiru, Feb 23 2019

Mathematica

Select[Range[300],DigitCount[#,10,7]>0&] (* Harvey P. Dale, Mar 29 2016 *)

PARI

is(n)=!!setsearch(Set(digits(n)), 7) \\ Charles R Greathouse IV, Feb 12 2017

Python

def ok(n): return '7' in str(n)
print(list(filter(ok, range(290)))) # Michael S. Branicky, Jul 17 2021

Formula

a(n) ~ n. - Charles R Greathouse IV, Feb 12 2017