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

Author

Martin Y. Champel, Apr 09 2015

Keywords

• easy
• nonn

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.

Examples

			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.
		

Programs

Python

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]))