A065086 Number of n-digit biquanimous numbers in base 10 not allowing leading zeros.

1, 9, 126, 1920, 27190, 347168, 3990467, 42744527, 440764556, 4464045276, 44863859589, 449488519847, 4498059105204, 44992451829730, 449969622539954, 4499873022468708, 44999449703306768, 449997540235466340, 4499988731927483569, 44999947410278947807

Offset

1,2

Comments

A biquanimous number (A064544) is a number whose digits can be split into two groups with equal sums.

References

William P. Thurston, personal communication.

Links

Table of n, a(n) for n=1..20.

Example

a(1) = 1 since 0 is the only 1-digit biquam. a(2) = 9 because there are 9 2-digit biquams, namely 11, 22, 33, 44, 55, 66, 77, 88 and 99.

Crossrefs

Cf. A064544, A065023, A065025, A065024.

Sequence in context: A229283 A144073 A261801 * A246238 A234573 A306033

Adjacent sequences: A065083 A065084 A065085 * A065087 A065088 A065089

Keyword

nonn,base

Author

David W. Wilson, Nov 07 2001

Status

approved