login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076389 Sum of squares of numbers that cannot be written as t*n + u*(n+1) for nonnegative integers t,u. 7
0, 1, 30, 220, 950, 3045, 8036, 18480, 38340, 73425, 131890, 224796, 366730, 576485, 877800, 1300160, 1879656, 2659905, 3693030, 5040700, 6775230, 8980741, 11754380, 15207600, 19467500, 24678225, 31002426, 38622780, 47743570 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

Fred. Schuh, Vragen betreffende een onbepaalde vergelijking, Nieuw Tijdschrift voor Wiskunde, 52 (1964-1965) 193-198.

LINKS

Table of n, a(n) for n=1..29.

FORMULA

n^2*(n^2-1)*(n^2-n-1)/12. G.f.:(1+23*x+31*x^2+5*x^3)*x^2/(1-x)^7

MAPLE

seq(n^2*(n^2-1)*(n^2-n-1)/12, n=1..40);

CROSSREFS

Cf. A002417.

Sequence in context: A042754 A215192 A244836 * A189410 A210101 A156372

Adjacent sequences:  A076386 A076387 A076388 * A076390 A076391 A076392

KEYWORD

easy,nonn

AUTHOR

Floor van Lamoen, Oct 09 2002

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 23 13:55 EDT 2017. Contains 292358 sequences.