The On-Line Encyclopedia of Integer Sequences (OEIS)

A134193 revision #4

A134193

a(1) = 1; for n>1, a(n) = the smallest positive integer not occurring among the exponents in the prime-factorization of n.

1, 2, 2, 1, 2, 2, 2, 1, 1, 2, 2, 3, 2, 2, 2, 1, 2, 3, 2, 3, 2, 2, 2, 2, 1, 2, 1, 3, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 1, 3, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 3, 1, 2, 2, 2, 3, 2, 2, 2, 1, 2, 2, 3, 3, 2, 2, 2, 2, 1, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 2, 3, 3, 1, 2, 2, 2, 2, 2, 2

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..106.

EXAMPLE

The prime factorization of 24 is 2^3 * 3^1. The exponents are 3 and 1. Therefore a(24) = 2 is the smallest positive integer not occurring among (3,1).

MATHEMATICA

Table[Complement[Range[n], Table[FactorInteger[n][[i, 2]], {i, 1, Length[FactorInteger[n]]}]][[1]], {n, 2, 120}] - Stefan Steinerberger, Jan 21 2008

CROSSREFS

Sequence in context: A072463 A128853 A136165 * A230259 A085030 A078377

Adjacent sequences: A134190 A134191 A134192 * A134194 A134195 A134196

KEYWORD

nonn

AUTHOR

Leroy Quet Jan 13 2008

EXTENSIONS

More terms from Stefan Steinerberger, Jan 21 2008

STATUS

approved