A352947 Prime numbers representing a date based on the proleptic Gregorian calendar in YY..YMMDD format.

10103, 10111, 10211, 10223, 10301, 10303, 10313, 10321, 10331, 10427, 10429, 10501, 10513, 10529, 10531, 10601, 10607, 10613, 10627, 10709, 10711, 10723, 10729, 10831, 10903, 10909, 11003, 11027, 11113, 11117, 11119, 11213, 20101, 20107, 20113, 20117, 20123

Offset

1,1

Links

Table of n, a(n) for n=1..37.

Example

20050403 is a term because the date 'Apr 3, 2005' represented in YY..YMMDD format is 20050403, which is a prime number.

Prog

(Python)
from sympy import isprime
for y in range(1, 3):
    for m in range(1, 13):
        d_max = 31 if m in {1, 3, 5, 7, 8, 10, 12} else 30 if m in {4, 6, 9, 11} else 28 if (y%4 or (y%400 and not y%100)) else 29
        for d in range(1, d_max + 1):
            date = 10000*y + 100*m + d
            if isprime(date): print(date, end = ', ')

Crossrefs

Cf. A227407, A227409, A354422.

Sequence in context: A395400 A227407 A227409 * A260247 A058042 A191244

Adjacent sequences: A352944 A352945 A352946 * A352948 A352949 A352950

Keyword

nonn,base

Author

Ya-Ping Lu, Apr 10 2022

Status

approved