cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-7 of 7 results.

A060345 An expansion related to Yukawa coupling.

Original entry on oeis.org

5, 2875, 4876875, 8564575000, 15517926796875, 28663236110956000, 53621944306062201000, 101216230345800061125625, 192323666400003538944396875, 367299732093982242625847031250, 704288164978454714776724365580000, 1354842473951260627644461070753075500, 2613295702542192770504516764304958585000
Offset: 0

Views

Author

N. J. A. Sloane, Mar 30 2001

Keywords

Comments

Coefficients of 3-point function in dimension 3 [Morrison].

Examples

			a(10) = A060041(1) + 8*A060041(2) + 125*A060041(5) + 1000*A060041(10) = 704288164978454714776724365580000.
		

Crossrefs

Programs

  • PARI
    cumsum(v) = for(i=2, #v, v[i] += v[i-1]); v;
    seq(N, {d=5}) = {
      my(x = 'x + O('x^(N+1)), h = cumsum(vector(d*N, n, 1/n)),
         y0 = sum(n=0, N, (d*n)!/n!^d * x^n),
         y1 = d * sum(n = 1, N, ((d*n)!/n!^d * (h[d*n] - h[n])) * x^n),
         Qx = x * exp(y1/y0), Xq = serreverse(Qx));
      Vec(d * (x * Xq'/Xq)^(d-2) / ((1 - d^d*Xq) * sqr(subst(y0, 'x, Xq))));
    };
    seq(20)  \\ Gheorghe Coserea, Jul 29 2016

Formula

Sum_{n >= 0} a(n)*q^n = 5 + Sum_{n >= 1} A060041(n)*n^3*q^n/(1-q^n).

Extensions

More terms from Vladeta Jovovic, Apr 01 2001
a(6) corrected and a(10)-a(12) added by Gheorghe Coserea, Jul 28 2016

A076912 Number of degree-n rational curves on a general quintic threefold.

Original entry on oeis.org

5, 2875, 609250, 317206375, 242467530000, 229305888887625, 248249742118022000, 295091050570845659250, 375632160937476603550000, 503840510416985243645106250, 704288164978454686113382643750
Offset: 0

Views

Author

N. J. A. Sloane, Nov 28 2002

Keywords

Examples

			a(1) = 2875 = number of lines in the quintic.
		

References

  • J. Bertin and C. Peters, Variations of Hodge structure ..., pp. 151-232 of J. Bertin et al., eds., Introduction to Hodge Theory, Amer. Math. Soc. and Soc. Math. France, 2002; see p. 220.
  • D. A. Cox and S. Katz, Mirror Symmetry and Algebraic Geometry, Amer. Math. Soc., 1999.
  • Ellingsrud, Geir and Stromme, Stein Arild, The number of twisted cubic curves on the general quintic threefold (preliminary version). In Essays on Mirror Manifolds, 181-222, Int. Press, Hong Kong, 1992.

Crossrefs

Coincides with A060041 for n <= 9, but not for n = 10.

Extensions

a(10) = A060041(10) - 6 * 17601000 added by Andrey Zabolotskiy, Sep 10 2022 (see Encyclopedia of Mathematics, Clemens' conjecture)

A090005 Gromov-Witten invariants of intersection type (3,3).

Original entry on oeis.org

1053, 52812, 6424326, 1139448384, 249787892583, 62660964509532, 17256453900822009, 5088842568426162960, 1581250717976557887945, 512045241907209106828608
Offset: 1

Views

Author

N. J. A. Sloane, Jan 28 2004

Keywords

References

  • J. Bertin and C. Peters, Variations of Hodge structure ..., pp. 151-232 of J. Bertin et al., eds., Introduction to Hodge Theory, Amer. Math. Soc. and Soc. Math. France, 2002.

Crossrefs

A090008 Gromov-Witten invariants of intersection type (2,2,3).

Original entry on oeis.org

720, 22428, 1611504, 168199200, 21676931712, 3195557904564, 517064870788848, 89580965599606752, 16352303769375910848, 3110686153486233022944
Offset: 1

Views

Author

N. J. A. Sloane, Jan 28 2004

Keywords

References

  • J. Bertin and C. Peters, Variations of Hodge structure ..., pp. 151-232 of J. Bertin et al., eds., Introduction to Hodge Theory, Amer. Math. Soc. and Soc. Math. France, 2002.

Crossrefs

A090006 Gromov-Witten invariants of intersection type (2,4).

Original entry on oeis.org

1280, 92288, 15655168, 3883902528, 1190923282176, 417874605342336, 160964588281789696, 66392895625625639488, 28855060316616488359936, 13069047760169269024822656
Offset: 1

Views

Author

N. J. A. Sloane, Jan 28 2004

Keywords

References

  • J. Bertin and C. Peters, Variations of Hodge structure ..., pp. 151-232 of J. Bertin et al., eds., Introduction to Hodge Theory, Amer. Math. Soc. and Soc. Math. France, 2002.

Crossrefs

A090007 Gromov-Witten invariants of intersection type (2,2,2,2).

Original entry on oeis.org

512, 9728, 416256, 25703936, 1957983744, 1705359223200, 16300354777600, 1668063096387072, 179845756064329728, 20206497983891554816
Offset: 1

Views

Author

N. J. A. Sloane, Jan 28 2004

Keywords

References

  • J. Bertin and C. Peters, Variations of Hodge structure ..., pp. 151-232 of J. Bertin et al., eds., Introduction to Hodge Theory, Amer. Math. Soc. and Soc. Math. France, 2002.

Crossrefs

A308279 The weighted sum of BPS states n_1^n for the quintic.

Original entry on oeis.org

0, 0, 609250, 3721431625, 12129909700200, 31147299733286500, 71578406022880761750, 154990541752961568418125, 324064464310279585657008750, 662863774391414096742406576300, 1336442091735463067608016312923750, 2668147157687867719032781403203942875, 5290387928421738826068606777043538125500
Offset: 1

Views

Author

Seiichi Manyama, May 18 2019

Keywords

Crossrefs

Cf. A060041.
Showing 1-7 of 7 results.