%I
%S 1589,1595,1606,1617,1623,1634,1645,1651,1662,1673,1679,1690,1702,
%T 1713,1719,1730,1741,1747,1758,1769,1775,1786,1797,1809,1815,1826,
%U 1837,1843,1854,1865,1871,1882,1893,1899,1905,1911,1922,1933,1939,1950,1961,1967,1978,1989,1995
%N Nonleap years beginning and ending on Sunday.
%C Gregorian calendar repeats after every 400 years because number of days in 400 years is 146097 which is a multiple of 7.
%C Noncentury 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 43 occurrences in 400 years.
%C Months having Friday the 13th: January and October.
%C 365 day ordinary year: 53 Sundays, 52 Mondays, 52 Tuesdays, 52 Wednesdays, 52 Thursdays, 52 Fridays, 52 Saturdays.
%H Time and Date, <a href="http://www.timeanddate.com/calendar/gregoriancalendar.html">The Gregorian calendar</a>
%H Time and Date, <a href="http://www.timeanddate.com/calendar/?year=2006">2006</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Gregorian_calendar">Gregorian calendar</a>
%t Select[Range[1583, 2600], DayOfWeek[{#, 1, 1}, Calendar > Gregorian] == Sunday && DaysBetween[{#, 1, 1}, {# + 1, 1, 1}, Calendar > Gregorian] == 365 &, 50] (* _T. D. Noe_, Apr 22 2013 *)
%K nonn
%O 1,1
%A _Aswini Vaidyanathan_, Apr 21 2013
