|
| |
|
|
A050410
|
|
Truncated square pyramid numbers: a(n)=sum(k^2,k=n..2*n-1).
|
|
3
| |
|
|
0, 1, 13, 50, 126, 255, 451, 728, 1100, 1581, 2185, 2926, 3818, 4875, 6111, 7540, 9176, 11033, 13125, 15466, 18070, 20951, 24123, 27600, 31396, 35525, 40001, 44838, 50050, 55651, 61655, 68076, 74928, 82225, 89981, 98210, 106926, 116143
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
COMMENTS
| Starting with offset 1 = binomial transform of [1, 12, 25, 14, 0, 0, 0,...]. [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 09 2009]
|
|
|
FORMULA
| a(n)=n*(7*n-1)*(2*n-1)/6.
|
|
|
EXAMPLE
| 1^2 + 1; 2^2 + 3^2 = 13; 3^2 + 4^2 + 5^2 = 50; ...
|
|
|
MAPLE
| seq(add((n+k+1)^2, k=0..n), n=-1..36); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 01 2006
|
|
|
PROG
| (PARI) for(n=1, 100, print1(sum(i=0, n-1, (n+i)^2), ", "))
|
|
|
CROSSREFS
| Cf. A072474.
Sequence in context: A147481 A197663 A189054 * A121991 A121990 A050491
Adjacent sequences: A050407 A050408 A050409 * A050411 A050412 A050413
|
|
|
KEYWORD
| easy,nice,nonn
|
|
|
AUTHOR
| Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Dec 22 1999
|
| |
|
|
