A068792 a(n) = (n-1)*n^(n-2) + Sum_{i=1..n} (n-i)*(n^(n-i-1) + n^(n+i-3)).
1, 16, 441, 24336, 2418025, 384473664, 89755965649, 28953439105600, 12345678987654321, 6727499948806851600, 4562491230669011577289, 3769449794266138309731600, 3727710895159027432980276121, 4348096581244536814777202995456, 5907679981266292758213173560296225
Offset: 2
Keywords
Examples
a(8) = 89755965649 = (1234567654321)OCT; a(10) = 12345678987654321 = A057139(9); a(16) = 5907679981266292758213173560296225 = (123456789ABC...987654321)HEX.
Links
- G. C. Greubel, Table of n, a(n) for n = 2..215
Programs
-
Magma
[((n^(n-1) -1)/(n-1))^2: n in [2..30]]; // G. C. Greubel, Aug 16 2022
-
Mathematica
Table[((n^(n-1) -1)/(n-1))^2, {n,2,30}] (* G. C. Greubel, Aug 16 2022 *) -
Python
def A068792(n): return ((n**(n-1)-1)//(n-1))**2 # Chai Wah Wu, Mar 18 2024
-
SageMath
[((n^(n-1) -1)/(n-1))^2 for n in (2..30)] # G. C. Greubel, Aug 16 2022
Formula
Extensions
More terms from G. C. Greubel, Aug 16 2022
Comments