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.

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.

Links

Table of n, a(n) for n=0..25.

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

Adjacent sequences: A256746 A256747 A256748 * A256750 A256751 A256752

Keyword

easy,nonn

Author

Martin Y. Champel, Apr 09 2015

Status

approved