A308415 Number of irreducible Egyptian fractions of denominator n which are the sum of 3 unit fractions.

3, 3, 5, 5, 8, 5, 10, 8, 11, 8, 13, 8, 15, 10, 13, 12, 18, 11, 19, 14, 19, 13, 22, 14, 22, 15, 22, 18, 24, 13, 25, 20, 23, 18, 28, 18, 25, 20, 28, 22, 28, 19, 29, 24, 29, 20, 33, 24, 35, 23, 32, 27, 33, 22, 42, 28, 35, 24, 38, 24, 30, 26, 38, 31

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Cyril Banderier, Florian Luca, Francesco Pappalardi, Numerators of Egyptian fractions, 2019.

Example

There are a(2)=3 irreducible fractions with denominator n=2 which are the sums of 3 unit fractions: 1/2 = 1/8 + 1/8 + 1/4 and 3/2 = 1/2 + 1/2 + 1/2, and 5/2 = 1/1 + 1/1 + 1/2.

Crossrefs

Cf. A308219, A308220, A308221.

Sequence in context: A247577 A282207 A046200 * A063281 A362059 A117772

Adjacent sequences: A308412 A308413 A308414 * A308416 A308417 A308418

Keyword

nonn

Author

Cyril Banderier, May 25 2019

Status

approved