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A231011
Number of months after which a date can fall on the same day of the week, and the two months can have the same number of days, in the Julian calendar.
3
0, 3, 6, 8, 9, 14, 15, 17, 18, 20, 22, 23, 26, 29, 31, 32, 34, 35, 37, 38, 40, 43, 46, 52, 54, 55, 57, 60, 63, 64, 68, 69, 72, 75, 77, 78, 80, 81, 86, 89, 92, 94, 95, 98, 101, 103, 106, 109, 110, 112, 114, 115, 117, 118, 123, 124, 126, 127, 129, 132, 135, 140, 141, 147, 149, 150
OFFSET
0,2
COMMENTS
In the Julian calendar, a year is a leap year if and only if it is a multiple of 4 and all century years are leap years.
Assuming this fact, this sequence is periodic with a period of 336.
This is a subsequence of A231010.
LINKS
PROG
(PARI) m=[0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5]; n=[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]; y=vector(336, i, (m[((i-1)%12)+1]+((5*((i-1)\48)+(((i-1)\12)%4)-!((i-1)%48)-!((i-2)%48))))%7); x=vector(336, i, n[((i-1)%12)+1]+!((i-2)%48)); for(p=0, 336, for(q=0, 336, if(y[(q%336)+1]==y[((q+p)%336)+1]&&x[(q%336)+1]==x[((q+p)%336)+1], print1(p", "); break)))
CROSSREFS
Cf. A231006 (Gregorian calendar).
Sequence in context: A140516 A310140 A231006 * A196370 A005622 A072960
KEYWORD
nonn,easy
AUTHOR
Aswini Vaidyanathan, Nov 02 2013
STATUS
approved