Fwd: Proposed seq: Numbers with strictly increasing positive prime exponents

Maximilian Hasler maximilian.hasler at gmail.com
Thu Jul 3 16:04:56 CEST 2008

> jvp> Numbers with strictly increasing positive prime exponents.

> By definition, this should give A133811. For example 4=2^2 and 8=2^3 fulfill
> the requirement. So is the (tacit) intend to skip prime powers?

not necessarily - you allow well that an infinite number of exponents
are zero and thus smaller than preceding exponents ; thus one could
well understand tacitly that only exponents of primes which DO occur
in the factorization are concerned by the restriction.

> The actual problem is that 50=2*5^2, 98=2*7^2, 147=3*7^2 and perhaps
> others seem to be missing in A133811, which looks like an error to me and is

no: that seq says clearly "...the p_i are n successive primes" in the comment
which - I suppose - explains the "primally tight" in the definition.


Two recent additions to the OEIS spawn the following naive questions:
Is A141778 the same as A038977?
Is A141750 the same as A038957?

Richard Mathar

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