cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A224947 Leap years having 53 Tuesdays and Wednesdays.

Original entry on oeis.org

1608, 1636, 1664, 1692, 1704, 1732, 1760, 1788, 1828, 1856, 1884, 1924, 1952, 1980, 2008, 2036, 2064, 2092, 2104, 2132, 2160, 2188, 2228, 2256, 2284, 2324, 2352, 2380, 2408, 2436, 2464, 2492, 2504, 2532, 2560, 2588, 2628, 2656, 2684, 2724, 2752, 2780
Offset: 1

Views

Author

Aswini Vaidyanathan, Apr 21 2013

Keywords

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.
14 occurrences in 400 years.
Months having Friday the 13th: June.
February 29th falls on Friday.
366 day leap year: 52 Sundays, 52 Mondays, 53 Tuesdays, 53 Wednesdays, 52 Thursdays, 52 Fridays, 52 Saturdays.

Crossrefs

Programs

  • Mathematica
    Needs["Calendar`"]; Select[Range[1583, 2800], DayOfWeek[{#, 1, 1}, Calendar -> Gregorian] == Tuesday && DaysBetween[{#, 1, 1}, {# + 1, 1, 1}, Calendar -> Gregorian] == 366 &, 50] (* T. D. Noe, Apr 22 2013 *)
    Select[Range[1583,3000],LeapYearQ[{#}]&&DayName[{#,1,1}]==Tuesday&] (* Ray Chandler, Jul 26 2023, v9 or later, after Harvey P.Dale at A224945 *)