A381004 Primes ending in 777.

1777, 2777, 11777, 19777, 22777, 26777, 41777, 43777, 44777, 47777, 50777, 53777, 65777, 67777, 68777, 71777, 76777, 79777, 80777, 83777, 94777, 97777, 107777, 110777, 113777, 115777, 122777, 124777, 125777, 131777, 134777, 136777, 137777, 145777, 146777

Offset: 1

Author

Harvey P. Dale, Feb 11 2025

Keywords

• nonn
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A193552.

Programs

Maple

select(isprime, [i*1000+777$i=1..150])[];  # Alois P. Heinz, Feb 12 2025

Mathematica

Select[Table[1000 n + 777, {n, 200}], PrimeQ]

PARI

select(x->((x % 1000)==777), primes(20000)) \\ Michel Marcus, Feb 12 2025

PARI

select(isprime, vector(200, n, 1000*n+777)) \\ Michel Marcus, Feb 12 2025

Python

from itertools import count, islice
from sympy import isprime
def A381004_gen(): # generator of terms
    return filter(isprime,count(777,1000))
A381004_list = list(islice(A381004_gen(),20)) # Chai Wah Wu, Feb 12 2025

Formula

a(n) = 1000*A102343(n)+777. - R. J. Mathar, Feb 13 2025