A178554 -id:A178554 - cp's OEIS frontend

A178550 Primes with exactly one digit 1.

13, 17, 19, 31, 41, 61, 71, 103, 107, 109, 127, 137, 139, 149, 157, 163, 167, 173, 179, 193, 197, 199, 241, 251, 271, 281, 313, 317, 331, 401, 419, 421, 431, 461, 491, 521, 541, 571, 601, 613, 617, 619, 631, 641, 661, 691, 701, 719, 751, 761, 821, 881, 919, 941, 971, 991

Offset: 1

Lekraj Beedassy, May 29 2010

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Intersection of A043493 and A000040.

Cf. A038618, A178551, A178552, A178553, A178554, A178555, A178556, A178557, A178558.

Select[Prime[Range[200]],Count[IntegerDigits[#],1]==1 &] (* Stefano Spezia, Aug 29 2025 *)

from sympy import isprime
print([i for i in range(1000) if str(i).count('1') == 1 and isprime(i)]) # Daniel Starodubtsev, Mar 29 2020

a(n) >> n^k where k = log(10)/log(9) = 1.04795.... - Charles R Greathouse IV, Jan 21 2025

A178551 Primes with exactly two 2's.

Original entry on oeis.org

223, 227, 229, 1223, 1229, 2027, 2029, 2129, 2203, 2207, 2213, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2423, 2521, 2621, 2729, 2927, 3221, 3229, 4229, 5227, 6221, 6229, 7229, 8221, 9221, 9227, 10223, 12203, 12211, 12239, 12241, 12251, 12253

Offset: 1

Lekraj Beedassy, May 29 2010

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Cf. A038618, A178550, A178552, A178553, A178554, A178555, A178556, A178557, A178558.

Select[Prime[Range[1500]],Count[IntegerDigits[#],2]==2 &] (* Stefano Spezia, Aug 29 2025 *)

from sympy import isprime
print([i for i in range(10000) if str(i).count('2') == 2 and isprime(i)]) # Daniel Starodubtsev, Mar 29 2020

A178553 Primes with exactly four 4's.

Original entry on oeis.org

44449, 404449, 440441, 440443, 441443, 441449, 442447, 444043, 444047, 444341, 444343, 444347, 444349, 444401, 444403, 444421, 444461, 444463, 444469, 444473, 444487, 444547, 444641, 444649, 444841, 445447, 446441, 446447, 447443, 447449, 449441

Offset: 1

Lekraj Beedassy, May 29 2010

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Cf. A038618, A178550, A178551, A178552, A178554, A178555, A178556, A178557, A178558.

isok(p) = isprime(p) && (#select(x->(x==4), digits(p)) == 4); \\ Michel Marcus, Mar 15 2020

Missing a(13) = 444349 inserted by Daniel Starodubtsev, Mar 15 2020

A178555 Primes with exactly six 6's.

Original entry on oeis.org

16666669, 26666663, 26666669, 46666661, 46666663, 56666663, 60666667, 63666661, 64666661, 64666663, 64666669, 66066661, 66166663, 66466661, 66466667, 66466669, 66606667, 66616663, 66626663, 66646667, 66656663

Offset: 1

Lekraj Beedassy, May 29 2010

Robert Israel, Table of n, a(n) for n = 1..10000

Cf. A038618, A178550-A178554, A178556-A178558.

f:= proc(m) local R, L, s, k, t,x;
  R:= NULL;
  for k from 9^(m-6) to 2*9^(m-6)-1 do
    t:= Vector(subs([8=9,7=8,6=7],convert(k,base,9)[1..m-6]));
    for s in combinat:-choose([$2..m],m-7) do
      L:= Vector(m,6);
      L[[1,op(s)]]:= t;
    if L[-1] = 0 then next fi;
      x:= add(L[i]*10^(i-1),i=1..m);
      if isprime(x) then R:= R, x fi;
  od od:
  op(sort([R]));
end proc:
f(8); # Robert Israel, May 08 2018

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A178550 Primes with exactly one digit 1.

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A178551 Primes with exactly two 2's.

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A178553 Primes with exactly four 4's.

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A178555 Primes with exactly six 6's.

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