%I #18 Jul 21 2024 20:00:04
%S 1587,1598,1609,1615,1626,1637,1643,1654,1665,1671,1682,1693,1699,
%T 1705,1711,1722,1733,1739,1750,1761,1767,1778,1789,1795,1801,1807,
%U 1818,1829,1835,1846,1857,1863,1874,1885,1891,1903,1914,1925,1931,1942,1953,1959,1970,1981,1987,1998
%N Non-leap years beginning and ending on Thursday.
%C Gregorian calendar repeats after every 400 years because number of days in 400 years is 146097 which is a multiple of 7.
%C Non-century years are leap years if and only if they are multiples of 4 while century years are leap years if and only if they are multiples of 400.
%C 44 occurrences in 400 years.
%C Months having Friday the 13th: February, March and November.
%C 365 day ordinary year: 52 Sundays, 52 Mondays, 52 Tuesdays, 52 Wednesdays, 53 Thursdays, 52 Fridays, 52 Saturdays.
%H Time and Date, <a href="http://www.timeanddate.com/calendar/gregorian-calendar.html">The Gregorian calendar</a>
%H Time and Date, <a href="http://www.timeanddate.com/calendar/?year=2009">2009</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Gregorian_calendar">Gregorian calendar</a>
%H <a href="/index/Ca#calendar">Index entries for sequences related to calendars</a>
%H <a href="/index/Rec#order_45">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).
%t Needs["Calendar`"]; Select[Range[1583, 2600], DayOfWeek[{#, 1, 1}, Calendar -> Gregorian] == Thursday && DaysBetween[{#, 1, 1}, {# + 1, 1, 1}, Calendar -> Gregorian] == 365 &, 50] (* _T. D. Noe_, Apr 22 2013 *)
%t Select[Range[1583,2600],!LeapYearQ[{#}]&&DayName[{#,1,1}]==DayName[ {#,12,31}] == Thursday&] (* _Harvey P. Dale_, May 06 2022, v9 or later *)
%Y Cf. A224938, A224939, A224940, A224941, A224943, A224944.
%K nonn
%O 1,1
%A _Aswini Vaidyanathan_, Apr 21 2013