A227407 Prime numbers representing a date in "condensed European notation" DDMMYY.

10103, 10111, 10133, 10139, 10141, 10151, 10159, 10163, 10169, 10177, 10181, 10193, 10211, 10223, 10243, 10247, 10253, 10259, 10267, 10271, 10273, 10289, 10301, 10303, 10313, 10321, 10331, 10333, 10337, 10343, 10357, 10369, 10391, 10399, 10427, 10429, 10433

Offset: 1

Author

Shyam Sunder Gupta, Sep 22 2013

Keywords

• nonn
• base
• fini
• full
• less

Comments

For February, the number of days will be 28 only, as the year cannot be a leap year if DDMMYY is to be a prime number.

The sequence is finite, with 3111 terms. The largest term is a(3111)=311299.

Examples

			a(1)=10103 is prime and represents a date in DDMMYY format as 010103.
		

Links

• Shyam Sunder Gupta, Table of n, a(n) for n = 1..3111

Crossrefs

Cf. A213182, A227409.

Programs

Mathematica

t = {}; Do[If[m < 8, If[OddQ[m], b = 31, If[m == 2, b = 28, b = 30]],If[OddQ[m], b = 30, b = 31]];Do[a = 100 m + y + 10000 d;If[PrimeQ[a], AppendTo[t, a]], {d, 1, b}], {m, 1, 12}, {y, 1, 99}]; Union[t]