

A090958


Numbers in increasing order such that the least multiple of prime(n) in the sequence is primorial(n).


1



1, 2, 4, 6, 8, 9, 12, 16, 18, 24, 27, 30, 32, 36, 40, 45, 48, 50, 54, 60, 64, 72, 75, 80, 81, 90, 96, 100, 108, 120, 125, 128, 135, 144, 150, 160, 162, 180, 192, 200, 210, 216, 224, 225, 240, 243, 245, 250, 252, 256, 270, 280, 288, 294, 300, 315, 320, 324, 336, 343
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OFFSET

0,2


COMMENTS

The sequence is obtained by including all those numbers between primorial(n) and primorial(n+1) which have the largest prime divisor < = prime(n).


LINKS

Table of n, a(n) for n=0..59.


MATHEMATICA

{{1}}~Join~Array[Function[{p, q}, Select[Range[p, p NextPrime[q]  1], FactorInteger[#][[1, 1]] <= q &]] @@ {Product[Prime@ i, {i, #}], Prime[#]} &, 4] // Flatten (* Michael De Vlieger, Nov 18 2017 *)


PROG

(PARI) v = vector(1000); pr = 1; forprime(p = 2, 1000, pr *= p; v[p] = pr); for (n = 2, 1000, f = factor(n); p = f[matsize(f)[1], 1]; if (n >= v[p], print(n))); \\ David Wasserman, Feb 22 2006


CROSSREFS

Cf. A090959.
Sequence in context: A324521 A146982 A298305 * A245047 A074901 A189294
Adjacent sequences: A090955 A090956 A090957 * A090959 A090960 A090961


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Dec 31 2003


EXTENSIONS

More terms from David Wasserman, Feb 22 2006


STATUS

approved



