A242063 Analog clock times where the minute hand is on the hour hand (in hhmm format).

0, 105, 211, 316, 422, 527, 633, 738, 844, 949, 1055

Offset: 1

Author

Jon Perry, Aug 13 2014

Keywords

• fini
• full
• nonn

Comments

The format is loosely defined - leading zeros of both hours and minutes disappear.

Changing the tolerance in the JavaScript program changes the results - try 0.01 for example, and we are allowed 10:54.

It is debatable whether 00:00 should be 12:00, but I have used 00:00. As the clock is analog, 13:05 is not valid - am and pm is usually left to discretion.

Examples

			At 04:22 the minute hand covers the hour hand.
		

Links

• Maths is Fun, Analog Clock
• Maths is Fun, Set the time
• NAWCC, How do clocks work?
• Wikipedia, Clocks
• Wikipedia, Watches

Crossrefs

Cf. A178181, A183032, A183033.

Programs

JavaScript

for (h=0;h<12;h++)
for (m=0;m<60;m++)
if (Math.abs(h/12+m/720-m/60)<0.007) {if (m<10) m="0"+m;document.write(h.toString()+m+", ");}

Formula

a(n) = a(n-1) + a(n-2) - a(n-3) for n=4..11. - Colin Barker, Aug 19 2014

a(n) = (-423 - (-1)^n + 422*n)/4 for n=1..11. - Colin Barker, Aug 19 2014