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.

A017895 Expansion of 1/(1-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19).

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 11, 13, 16, 20, 25, 31, 38, 46, 55, 64, 73, 83, 95, 110, 129, 153, 183, 220, 265, 319, 381, 451, 530, 620, 724, 846, 991, 1165, 1375, 1630, 1938, 2306, 2741, 3251, 3846, 4539, 5347, 6292, 7402, 8713, 10270
Offset: 0

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Comments

Number of compositions (ordered partitions) of n into parts 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19. - Ilya Gutkovskiy, May 27 2017

Crossrefs

Cf. A017887.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 80);
    Coefficients(R!(1/(1-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19))); // Vincenzo Librandi, Jul 01 2013
    
  • Mathematica
    CoefficientList[Series[1 / (1 - Total[x^Range[10, 19]]), {x, 0, 70}], x] (* Vincenzo Librandi Jul 01 2013 *)
    LinearRecurrence[{0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1},{1,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1},80] (* Harvey P. Dale, Apr 07 2025 *)
  • SageMath
    def A017895_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-x)/(1-x-x^10+x^20) ).list()
    A017895_list(81) # G. C. Greubel, Nov 08 2024

Formula

a(n) = a(n-10) +a(n-11) +a(n-12) +a(n-13) +a(n-14) +a(n-15) +a(n-16) +a(n-17) +a(n-18) +a(n-19) for n>18. - Vincenzo Librandi, Jul 01 2013