A107731 Row 7 of the array in A107735.

1, 21, 141, 521, 1401, 3101, 6021, 10641, 17521, 27301, 40701, 58521, 81641, 111021, 147701, 192801, 247521, 313141, 391021, 482601, 589401, 713021, 855141, 1017521, 1202001, 1410501, 1645021, 1907641, 2200521, 2525901, 2886101, 3283521

Offset

0,2

References

S. Mukai, An Introduction to Invariants and Moduli, Cambridge, 2003; see p. 483.

Links

Table of n, a(n) for n=0..31.

Formula

a(n) = 1 + (n^2+n)*(n^2+n+1)*10/3. a(-1-n)= a(n). - Michael Somos, Mar 20 2007

G.f.: (1 + 16*x + 46*x^2 + 16*x^3 + x^4)/(1-x)^5. - Michael Somos, Mar 20 2007; corrected by Georg Fischer, Apr 17 2020

Mathematica

nn:=31; CoefficientList[Series[(1 + 16*x + 46*x^2 + 16*x^3 + x^4)/(1-x
)^5, {x, 0, nn}], x] (* Georg Fischer, Apr 17 2020 *)

Prog

(PARI) {a(n)= 1+ (n^2+n)* (n^2+n+1)* 10/3} /* Michael Somos, Mar 20 2007 */

Crossrefs

Sequence in context: A220151 A337899 A200987 * A003702 A221785 A301866

Adjacent sequences: A107728 A107729 A107730 * A107732 A107733 A107734

Keyword

nonn

Author

N. J. A. Sloane, Jun 10 2005

Extensions

More terms from Michael Somos, Mar 20 2007

Status

approved