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A130638 a(n) = 1 iff d(n) = d(n+1), otherwise a(n)=0; where d(n) is the number of divisors of natural number. 0
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Index entries for characteristic functions

MATHEMATICA

Table[If[Length[Divisors[n]] == Length[Divisors[n + 1]], 1, 0], {n, 1, 80}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 12 2007

CROSSREFS

Sequence in context: A063524 A084928 A033683 * A030217 A030215 A098108

Adjacent sequences:  A130635 A130636 A130637 * A130639 A130640 A130641

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Aug 11 2007

EXTENSIONS

Corrected and extended by Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 12 2007

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Last modified February 15 11:25 EST 2012. Contains 205777 sequences.