The On-Line Encyclopedia of Integer Sequences (OEIS)

A293449 revision #4

A293449

Characteristic function for numbers that have no nonprime exponents present in their prime factorization n = p_1^e_1 * ... * p_k * e_k.

1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 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, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

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OFFSET

COMMENTS

After a(1) = 1 numbers such that only primes occur as exponents in their prime factorization.

LINKS

Table of n, a(n) for n=1..120.

Index entries for characteristic functions

Index entries for sequences computed from exponents in factorization of n

EXAMPLE

For n = 4 = 2^2, 2 is prime, thus a(4) = 1.

For n = 12 = 2^2 * 3^1, 2 is prime, but 1 is not, thus a(12) = 0.

For n = 16 = 2^4, 4 is not prime, thus a(16) = 0.