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Years in which there are five Thursdays in the month of February, in the Gregorian calendar.
8

%I #23 Jul 26 2023 20:35:56

%S 1776,1816,1844,1872,1912,1940,1968,1996,2024,2052,2080,2120,2148,

%T 2176,2216,2244,2272,2312,2340,2368,2396,2424,2452,2480,2520,2548,

%U 2576,2616,2644,2672,2712,2740,2768,2796,2824,2852,2880,2920,2948,2976,3016,3044

%N Years in which there are five Thursdays in the month of February, in the Gregorian calendar.

%H <a href="/index/Ca#calendar">Index entries for sequences related to calendars</a>

%H <a href="/index/Rec#order_14">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).

%p A143995 := proc(n) nper := (n-1) mod 13 ; floor((n-1)/13)*400+op(1+nper , [1776, 1816, 1844, 1872, 1912, 1940, 1968, 1996, 2024, 2052, 2080, 2120, 2148] ) ; end proc: seq(A143995(n), n=1..80) ; # _R. J. Mathar_, Mar 29 2010

%t (* Needs Mma version >= 9.0 *)

%t okQ[y_] := LeapYearQ[{y}] && DayName[{y, 2, 1}] == Thursday;

%t Select[Range[1752, 3051, 4], okQ] (* _Jean-François Alcover_, Mar 27 2020 *)

%Y Cf. A119406 (Sun), A135795 (Mon), A143994 (Tue), A141039 (Wed), A141287 (Fri), A176478 (Sat).

%K nonn

%O 1,1

%A _J. Lowell_, Sep 07 2008

%E More terms from _R. J. Mathar_, Mar 29 2010