|
Search: id:A076457
|
|
|
| A076457 |
|
Sum of numbers that can be written as t*n + u*(n+1) for nonnegative integers t,u in exactly four ways. |
|
+0
1
|
|
| 13, 129, 534, 1510, 3435, 6783, 12124, 20124, 31545, 47245, 68178, 95394, 130039, 173355, 226680, 291448, 369189, 461529, 570190, 696990, 843843, 1012759, 1205844, 1425300, 1673425, 1952613, 2265354, 2614234, 3001935, 3431235
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
REFERENCES
|
Fred. Schuh, Vragen betreffende een onbepaalde vergelijking, Nieuw Tijdschrift voor Wiskunde, 52 (1964-1965) 193-198.
|
|
FORMULA
|
1/2*n*(n+1)*(8*n^2+6*n-1). G.f.: x*(19*x^2+64*x+13)/((1+x)*(1-x)^5).
|
|
MAPLE
|
seq(1/2*n*(n+1)*(8*n^2+6*n-1), n=1..40);
|
|
CROSSREFS
|
Cf. A002417, A076454-A076459.
Sequence in context: A125401 A089763 A124298 this_sequence A016162 A023061 A121033
Adjacent sequences: A076454 A076455 A076456 this_sequence A076458 A076459 A076460
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Floor van Lamoen (fvlamoen(AT)hotmail.com), Oct 13 2002
|
|
|
Search completed in 0.002 seconds
|
