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.

A156194 Period 12: 1,2,7,1,7,2,1,1,4,2,4,1 repeated.

Original entry on oeis.org

1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1, 1, 2, 7, 1, 7, 2, 1, 1, 4, 2, 4, 1
Offset: 0

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Author

Paul Curtz, Feb 05 2009

Keywords

Comments

Also the decimal expansion of 42390704747/333333333333. - R. J. Mathar, Feb 23 2009

Programs

  • Mathematica
    PadRight[{},144,{1,2,7,1,7,2,1,1,4,2,4,1}] (* Harvey P. Dale, Mar 06 2012 *)

Formula

Palindromic properties: a(12k+i) = a(12k+6-i), i=0..3. a(12k+7+i) = a(12k+11-i), i=0..2, and similarly for successive differences.
a(n) = A156095(n) mod 9.
a(n) = A156094(n+6) mod 9.
a(4n) + a(4n+1) + a(4n+2) + a(4n+3) = A010850(n).
G.f.: (1+2*x+7*x^2+x^3+7*x^4+2*x^5+x^6+x^7+4*x^8+2*x^9+4*x^10+x^11)/((1-x)*(1+x+x^2)*(1+x)*(1-x+x^2)*(1+x^2)*(x^4-x^2+1)). - R. J. Mathar, Feb 23 2009

Extensions

Edited by R. J. Mathar, Feb 23 2009
More terms from Jinyuan Wang, Feb 26 2020