A109571 Prague bus clock sequence #2.

1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 9, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 9, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 129, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 249, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 9, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 9, 1, 1, 8, 1, 8, 1, 1, 28, 1, 129, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 249, 1, 1, 8, 1, 1, 8, 1, 1, 28, 1, 9

Offset: 1

Author

Eric Angelini and others, Aug 30 2005

Keywords

• base
• easy
• fini
• nonn

Comments

Start a digital clock at midnight; you read 00:00 (hours and minutes). Wait for 1 minute and read 00:01; if you look at 00:01 in a mirror, you'll see 10:00, which is a sound time on such a clock; wait for another minute and read 00:02; this gives the "mirror time" 20:00, which is sound; you must wait now for 8 minutes before seeing another sound "mirror time": 00:10 gives 01:00; etc. Successive waiting times form the sequence. The "mirror digit transform" is: 0->0, 1->1, 2->5, 5->2 and 8->8. "8" can't be used here and "5" must be carefully placed.

Examples

			Successive number of minutes one has to wait, starting at midnight, to read a sound "mirror" time on a digital clock.
		

Crossrefs

Cf. A028354, A109527.