A224941 Non-leap years beginning and ending on Wednesday.

1586, 1597, 1603, 1614, 1625, 1631, 1642, 1653, 1659, 1670, 1681, 1687, 1698, 1710, 1721, 1727, 1738, 1749, 1755, 1766, 1777, 1783, 1794, 1800, 1806, 1817, 1823, 1834, 1845, 1851, 1862, 1873, 1879, 1890, 1902, 1913, 1919, 1930, 1941, 1947, 1958, 1969, 1975, 1986, 1997

Offset

1,1

Comments

Gregorian calendar repeats after every 400 years because number of days in 400 years is 146097 which is a multiple of 7.

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.

43 occurrences in 400 years.

Months having Friday the 13th: June.

365 day ordinary year: 52 Sundays, 52 Mondays, 52 Tuesdays, 53 Wednesdays, 52 Thursdays, 52 Fridays, 52 Saturdays.

Links

Table of n, a(n) for n=1..45.

Time and Date, The Gregorian calendar

Time and Date, 2014

Wikipedia, Gregorian calendar

Index entries for sequences related to calendars

Index entries for linear recurrences with constant coefficients, 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, 1, -1).

Mathematica

Select[Range[1583, 2600], DayOfWeek[{#, 1, 1}, Calendar -> Gregorian] == Wednesday && DaysBetween[{#, 1, 1}, {# + 1, 1, 1}, Calendar -> Gregorian] == 365 &, 50] (* T. D. Noe, Apr 22 2013 *)
Select[Range[1583, 2500], !LeapYearQ[{#}]&&DayName[{#, 1, 1}]==DayName[{#, 12, 31}]==Wednesday&](* Ray Chandler, Jul 26 2023, Version 10, after _Harvey P.Dale_ at A224942 *)

Crossrefs

Cf. A224938, A224939, A224940, A224942, A224943, A224944.

Sequence in context: A235844 A277766 A224940 * A213116 A224942 A224950

Adjacent sequences: A224938 A224939 A224940 * A224942 A224943 A224944

Keyword

nonn

Author

Aswini Vaidyanathan, Apr 21 2013

Status

approved