A020449 Primes whose greatest digit is 1.

11, 101, 10111, 101111, 1011001, 1100101, 10010101, 10011101, 10100011, 10101101, 10110011, 10111001, 11000111, 11100101, 11110111, 11111101, 100100111, 100111001, 101001001, 101001011, 101100011, 101101111, 101111011, 101111111

Offset

1,1

Comments

Primes which are the sums of distinct powers of 10. - Amarnath Murthy, Nov 19 2002

Subsequence of A007088. - Michel Marcus, Dec 18 2015

These numbers are called Anti-Yarborough prime numbers in the Prime Glossary. - Randy L. Ekl, Jan 19 2019

Links

Jon E. Schoenfield, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)

C. K. Caldwell, The Prime Glossary, Yarborough prime.

Index to entries for primes with digits in a given set

Maple

N:= 10: # to get all entries with <= N digits
S:= {}:
for d from 1 to N-1 do
  S:= S union select(isprime, map(`+`, map(convert, combinat[powerset]({seq(10^i, i=0..d-1)}), `+`), 10^d));
od:
S; # if using Maple 11 or earlier, uncomment the next line
# sort(convert(%, list)); # Robert Israel, May 04 2015

Mathematica

Flatten[Table[Select[FromDigits/@Tuples[{0, 1}, n], PrimeQ], {n, 9}]] (* Vincenzo Librandi, Jul 27 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(101111111) | Set(Intseq(p)) subset [0, 1]]; // Vincenzo Librandi, Jul 27 2012
(PARI) is(n)=isprime(n)&&vecmax(digits(n))==1 \\ Charles R Greathouse IV, Jul 01 2013
(Python)
from sympy import isprime
A020449_list = [n for n in (int(format(m, 'b')) for m in range(1, 2**10)) if isprime(n)] # Chai Wah Wu, Dec 17 2015

Crossrefs

Cf. A007088, A036952.

Sequence in context: A064490 A080439 A098153 * A089971 A082620 A199304

Adjacent sequences: A020446 A020447 A020448 * A020450 A020451 A020452

Keyword

nonn,base

Author

David W. Wilson

Status

approved