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 1-2 of 2 results.

A128546 Inrepfigit (INverse REPetitive FIbonacci-like diGIT) numbers (or Htiek numbers).

Original entry on oeis.org

17, 21, 25, 42, 63, 84, 143, 286, 2355, 5821, 6618, 11709, 12482, 33747, 39571, 129109, 466957, 1162248, 1565166, 1968084, 3636638, 3853951, 4898376, 6065280, 13443745, 13933175, 17118698, 22421197, 24153462377
Offset: 1

Views

Author

Pierre Karpman (pierre.karpman(AT)laposte.net), Oct 23 2007

Keywords

Comments

This sequence is similar to A007629 (Keith numbers). It consists of the numbers n>9 with the following property: n is a term of the sequence S whose first k terms are the k digits of n (with the first term equal to the units digit) and with S(n+1)=sum of the k previous terms.

Examples

			42 is in the sequence because the terms of the sequence it creates are 2, 4, 6, 10, 16, 26, 42, ...

Crossrefs

Cf. A007629.
Cf. A097060 (reverse of these numbers).

Programs

  • Mathematica
    iKeithQ[n_Integer] := Module[{b = Reverse[IntegerDigits[n]], s, k = 0}, s = Total[b]; While[s < n, AppendTo[b, s]; k++; s = 2*s - b[[k]]]; s == n]; Select[Range[10, 100000], iKeithQ] (* T. D. Noe, Mar 15 2011 *)

A096428 Decimal expansion of (4*sqrt(2)*Pi^2)/gamma(1/4)^2.

Original entry on oeis.org

4, 2, 4, 7, 2, 9, 6, 5, 4, 5, 9, 6, 3, 8, 7, 8, 6, 5, 1, 2, 2, 1, 5, 1, 3, 1, 4, 9, 5, 9, 5, 7, 8, 8, 5, 2, 4, 0, 2, 2, 2, 3, 8, 5, 7, 8, 9, 3, 1, 5, 5, 6, 8, 4, 8, 1, 6, 2, 0, 0, 6, 0, 7, 3, 3, 5, 5, 9, 3, 3, 3, 8, 2, 2, 4, 4, 8, 4, 6, 4, 4, 9, 6, 5, 4, 7, 6, 0, 0, 4, 1, 7, 0, 3, 7, 8, 3, 6, 0, 8, 0, 3
Offset: 1

Views

Author

Eric W. Weisstein, Jul 21 2004

Keywords

Comments

Asymptotic constant in the expected perimeter of square point picking.

Examples

			4.247296545963878651221513149595788524022238578931556848162...

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.1 Geometric Probability Constants, p. 481.

Links

Crossrefs

Cf. A097060.

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); 4*Sqrt(2)*Pi(R)^2/Gamma(1/4)^2; // G. C. Greubel, Sep 27 2018
  • Mathematica
    RealDigits[(4*Sqrt[2]*Pi^2)/Gamma[1/4]^2, 10, 100][[1]] (* G. C. Greubel, Sep 27 2018 *)
  • PARI
    (4*sqrt(2)*Pi^2)/gamma(1/4)^2 \\ Michel Marcus, Jun 26 2014
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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