A379526 Number of ordered ways of writing 1 as Sum_{k=-n..n, k<>0} e(k)/k, where e(k) is 0 or 1.

1, 7, 133, 5419, 383785, 42244765, 6520970371, 1359532454017

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Example

a(2) = 7 ways: {1}, {-1/2, 1, 1/2} (6 permutations).

Crossrefs

Cf. A002967, A038034, A379335, A379451.

Sequence in context: A251577 A082164 A229464 * A317216 A119670 A003374

Adjacent sequences: A379523 A379524 A379525 * A379527 A379528 A379529

Keyword

nonn,more

Author

Ilya Gutkovskiy, Dec 24 2024

Status

approved