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.

A084185 First occurrence of binary n in the binary expansion of sqrt(2).

Original entry on oeis.org

1, 1, 3, 8, 1, 3, 17, 8, 14, 4, 1, 19, 3, 18, 17, 8, 62, 51, 14, 6, 4, 1, 42, 80, 19, 3, 41, 18, 40, 17, 31, 8, 57, 62, 128, 51, 69, 20, 14, 6, 104, 4, 111, 66, 1, 96, 42, 146, 80, 50, 19, 118, 3, 77, 41, 126, 18, 98, 40, 17, 75, 33, 31, 453, 8, 57
Offset: 1

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Author

Ralf Stephan, May 18 2003

Keywords

Comments

a(n)=1 iff n in A084188. a(2^(n+1)+1) = A084187(n)-1.

Examples

			The binary expansion of sqrt(2) is 1.0110101000001..(A004539) and binary(10)=1010 occurs first at index 4, so a(10)=4.
		

Crossrefs

Cf. A084186.

Programs

  • Mathematica
    With[{s2=RealDigits[Sqrt[2],2,1000][[1]],n2=IntegerDigits[n,2]}, Flatten[ Table[First[ Position[Partition[s2,Length[n2],1],n2]],{n,70}]]] (* Harvey P. Dale, Oct 11 2012 *)