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A256749
a(n) is the time expressed in seconds starting at 0:00:00 at which the second-hand of a classical three hands clock is passing over any of the two other hands considering the minute-hand turns of 6 degrees in one minute and the hour-hand of 6 degrees in 12 minutes.
1
0, 60, 61, 120, 122, 180, 183, 240, 244, 300, 305, 360, 366, 420, 427, 480, 488, 540, 549, 600, 610, 660, 671, 721, 732, 781
OFFSET
0,2
COMMENTS
The sequence is given for its first 1249 terms which corresponds to 12 hours. At 12:00:00 the clock is back to its initial state but as the time wheel keeps on turning a(1248) = 43200 + a(0) , a(1249) = 43200 + a(1), a(n + p*1248) = a(n) + p*43200 for any nonnegative integer p.
EXAMPLE
a(0) = 0 as the second-hand is over the minute-hand and the hour-hand at 0:00:00,
a(1) = 60 as the second-hand is over the hour-hand at 0:01:00,
a(2) = 61 as the second-hand is over the minute-hand at 0:01:01,...
a(23) = 721 as the second-hand is over the hour-hand at 0:12:01.
PROG
(Python 2.7)
m0 = 0
s = [0]
for i in range(1, 60*12+1):
....m0 += 1
....m = m0 % 60
....h = (m0 // 12) % 60
....a, b = i * 60 + h, i * 60 + m
....s.append(a)
....s.append(b)
s = list(sorted(set(s)))
for i in range(len(s)):
....print ('A256749('+str(i)+') = '+str(s[i]))
CROSSREFS
Sequence in context: A298688 A247437 A266916 * A280183 A181463 A114559
KEYWORD
easy,nonn
AUTHOR
Martin Y. Champel, Apr 09 2015
STATUS
approved