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A327915 The 59 prime dates of each leap year of the form concatenate(month,day) with leading zero for days 1..9. 6
101, 103, 107, 109, 113, 127, 131, 211, 223, 227, 229, 307, 311, 313, 317, 331, 401, 409, 419, 421, 503, 509, 521, 523, 601, 607, 613, 617, 619, 701, 709, 719, 727, 809, 811, 821, 823, 827, 829, 901, 911, 919, 929, 1009, 1013, 1019, 1021, 1031, 1103, 1109, 1117, 1123, 1129, 1201, 1213, 1217, 1223, 1229, 1231 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

In leap years all these dates come from the months January, February, ..., December, in the form  m.d, with a 0 in front of the days d = 1..9, with 7, 4, 5, 4, 4, 5, 4, 6, 4, 5, 5, 6 prime dates, respectively, adding up to 59. For the corresponding leap year case with 58 prime dates see A327914.

Compared with A327349 (leap years, no 0s before days d = 1..9) one has the same differences as given in a comment in A327914 (229 appears in the present sequence and in A327349).

LINKS

Table of n, a(n) for n=1..59.

MATHEMATICA

Select[Flatten@ Array[Function[{m, d}, Array[FromDigits[m~Join~PadLeft[IntegerDigits[#], 2]] &, d]] @@ {IntegerDigits@ #, Which[MemberQ[{4, 6, 9, 11}, #], 30, # == 2, 29, True, 31]} &, 12], PrimeQ] (* Michael De Vlieger, Oct 03 2019 *)

CROSSREFS

Cf. A327346 (74 prime dates d.m without leading 0 for month), A327347 (54 prime dates d.m with leading 0 for months m = 1, 3, 7, 9), A327348 (66 prime dates m.d for non-leap years), A327349 (67 prime dates, like A327348 but for leap years), A327914 (58 prime dates, the case for non-leap years).

Sequence in context: A195469 A210758 A225082 * A131687 A327914 A167844

Adjacent sequences:  A327912 A327913 A327914 * A327916 A327917 A327918

KEYWORD

nonn,easy,fini,full

AUTHOR

Wolfdieter Lang, Sep 30 2019

STATUS

approved

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Last modified December 16 09:06 EST 2019. Contains 330020 sequences. (Running on oeis4.)