A164768 First differences of A003592.

1, 2, 1, 3, 2, 6, 4, 5, 7, 8, 10, 14, 16, 20, 25, 3, 32, 40, 50, 6, 64, 80, 100, 12, 113, 15, 160, 200, 24, 226, 30, 320, 400, 48, 452, 60, 565, 75, 800, 96, 904, 120, 1130, 150, 1600, 192, 1808, 240, 2260, 300, 2825, 375, 384, 3616, 480, 4520, 600, 5650

Offset: 1

Author

Barry Wells (wells.barry(AT)gmail.com), Aug 26 2009, Sep 24 2009

Keywords

• nonn

Comments

The gaps between the natural numbers whose reciprocals are terminating decimals.

Examples

			The first few terms of A003592 are 1, 2, 4, 5, 8, 10, 16 because 1/1, 1/2, 1,4, 1/5, 1/8 etc. terminate and 1/3, 1/6, 1/7, 1/9 etc. repeat. Hence the denominators of the first few terminating decimals are 1, 2, 4, 5, 8, 10, 16 and the first differences between these gives the sequence 1,2,1,3,2,4
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..312 from Barry Wells)

Crossrefs

Cf. A003592.

Formula

a(n) = A003592(n+1) - A003592(n). - Amiram Eldar, Feb 08 2020