A068309 Number of different lucky numbers occurring when 2n is expressed as p1+q1 = ... = pk+qk where pk,qk are lucky numbers with pk <= qk.

1, 2, 1, 2, 4, 2, 3, 6, 3, 2, 6, 4, 3, 6, 3, 4, 8, 4, 6, 8, 3, 6, 10, 2, 7, 10, 4, 6, 10, 2, 5, 10, 5, 6, 10, 6, 9, 14, 6, 10, 14, 8, 7, 14, 6, 6, 14, 8, 5, 18, 9, 6, 14, 10, 6, 16, 10, 8, 16, 10, 6, 14, 9, 6, 18, 8, 5, 24, 11, 8, 24, 12, 7, 20, 11, 8, 16, 10

Offset

1,2

Comments

n=5: 10 = 1+9 = 3+7, we can see 4 different lucky numbers. so a(5) = 4.

Links

Table of n, a(n) for n=1..78.

Crossrefs

Cf. A000959, A002850.

Sequence in context: A279709 A261880 A119538 * A099470 A099254 A186731

Adjacent sequences: A068306 A068307 A068308 * A068310 A068311 A068312

Keyword

easy,nonn

Author

Naohiro Nomoto, Feb 25 2002

Extensions

More terms from Sean A. Irvine, Feb 08 2024

Status

approved