A178553 Primes with exactly four 4's.

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

1,1

Links

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

Prog

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

Crossrefs

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

Sequence in context: A115959 A045937 A138359 * A216203 A194355 A258514

Adjacent sequences: A178550 A178551 A178552 * A178554 A178555 A178556

Keyword

nonn,base

Author

Lekraj Beedassy, May 29 2010

Extensions

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

Status

approved