1,2

a(p) = 2^p - 1 for prime p

Table of n, a(n) for n=1..30.

a(4) = 12, because 12 is the smallest number with a binary run length product of 4.

12 decimal = 1100 binary. Run lengths in binary are 2,2, and 2x2 = 4.

Cf. A167489 - Product of run length in binary representation of n

Cf. A167491 - Numbers in this sequence sorted in ascending order

Sequence in context: A193297 A240738 A047068 * A081533 A096856 A108154

Adjacent sequences: A167487 A167488 A167489 * A167491 A167492 A167493

nonn

Andrew Weimholt, Nov 05 2009

approved