A327920 -id:A327920 - cp's OEIS frontend

A327918 The 16 pure prime dates of each non-leap year of the form concatenate(month,day) with month and day also prime numbers.

23, 211, 223, 37, 311, 313, 317, 331, 53, 523, 73, 719, 113, 1117, 1123, 1129

Offset: 1

Wolfdieter Lang, Oct 08 2019

For the numbers for leap years see A327919.
Only the months February (2), March (3), May (5), July (7) and November (11) qualify. The qualifying prime days are for month m=2: 3, 5, 7, 11, 13, 17, 19, 23; for month m = 11: 3, 5, 7, 11, 13, 17, 19, 23, 29 and for months m = 3, 5, and 7: 3, 5, 7, 11, 13, 17, 19, 23, 29, 31.
The months m = 2, 3, 5, 7, 11 contribute 3, 5, 2, 2, 4 days, respectively, adding to 16.

Cf. A165243 (first three terms), A165292 (first five terms), A165555 (first two terms), A167187 (first two terms), A327348 (m and d nonprime allowed), A327914 (with 0 before d = 1..9), A327919 (leap year), A327920 (pure prime dates of d.m form).

A327919 The 17 pure prime dates of each leap year of the form concatenate(month,day) with month and day also prime numbers.

Original entry on oeis.org

23, 211, 223, 229, 37, 311, 313, 317, 331, 53, 523, 73, 719, 113, 1117, 1123, 1129

Offset: 1

Wolfdieter Lang, Oct 08 2019

For the non-leap case see A327918.

The months m = 2, 3, 5, 7, 11 contribute 4, 5, 2, 2, 4 days, respectively, adding to 17.

Cf. A165243 (first four terms), A165292 (first five terms), A165555 (first two terms), A167187 (first two terms), A327349 (m and d nonprime allowed), A327915 (with 0 before d = 1..9), A327918 (non-leap year case), A327920 (pure prime dates of d.m form).

cp's OEIS Frontend

A327918 The 16 pure prime dates of each non-leap year of the form concatenate(month,day) with month and day also prime numbers.

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