|
|
A242604
|
|
a(n) = (n - 1)*(n^3 + 1) = n^4 - n^3 + n - 1, for n >= 1.
|
|
2
|
|
|
0, 9, 56, 195, 504, 1085, 2064, 3591, 5840, 9009, 13320, 19019, 26376, 35685, 47264, 61455, 78624, 99161, 123480, 152019, 185240, 223629, 267696, 317975, 375024, 439425, 511784, 592731, 682920, 783029, 893760, 1015839, 1150016, 1297065
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
1/a(n), for n >= 2, is in base n represented by 0.repeat(0,0,0,1,1,1). This is instance p = 3 of the general formula for 0.repeat(0^(q),1^(q)) (meaning here q zeros followed by q 1's) in base b >= 2 which is 1/a(q,b) with a(q,b) = (b - 1)*(b^p + 1), for p >= 1.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (n - 1)*(n^3 + 1) = n^4 - n^3 + n - 1, n >= 1.
O.g.f.: x^2*(9 + 11*x + 5*x^2 - x^3)/(1 - x)^5.
|
|
MAPLE
|
|
|
MATHEMATICA
|
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|