login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A240928 Number of 8-digit positive integers in base n where the sum of the first k digits equals the sum of the last k digits. 2
35, 750, 6174, 31025, 114961, 346193, 896876, 2072694, 4379055, 8606312, 15936426, 28073487, 47400509, 77164915, 121695128, 186650684, 279308283, 408886194, 586909430, 827618109, 1148421417, 1570399589, 2118856324, 2823924050, 3721224455, 4852586700 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

These integers are sometimes called balanced numbers.

REFERENCES

Cambridge Colleges Sixth Term Examination Papers (STEP) 2007, Paper I, Section A (Pure Mathematics), Nr. 1.

LINKS

Table of n, a(n) for n=2..27.

FORMULA

a(n) = n*(n-1)*(1208*n^5+151*n^4+291*n^3+116*n^2+88*n+60)/2520

CROSSREFS

Cf. A016061, A197083, A240927, A240929.

Sequence in context: A145603 A326865 A139641 * A028220 A334909 A028213

Adjacent sequences:  A240925 A240926 A240927 * A240929 A240930 A240931

KEYWORD

nonn,base

AUTHOR

Martin Renner, Aug 03 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 6 00:46 EDT 2021. Contains 346493 sequences. (Running on oeis4.)