The On-Line Encyclopedia of Integer Sequences (OEIS)

A133810 revision #4

A133810

Numbers that are primally tight and have weakly ascending powers.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 16, 17, 18, 19, 23, 25, 27, 29, 30, 31, 32, 35, 36, 37, 41, 43, 47, 49, 53, 54, 59, 61, 64, 67, 71, 73, 75, 77, 79, 81, 83, 89, 97, 101, 103, 105, 107, 108, 109, 113, 121, 125, 127, 128, 131, 137, 139, 143, 149, 150, 151, 157, 162

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

All numbers of the form p_1^k1*p_2^k2*...*p_n^k_n, where k1 <= k2 <= ... <= k_n and the p_i are n successive primes.

LINKS

Table of n, a(n) for n=1..65.

CROSSREFS

Cf. A025487, A087980, A073491, A133808-A133813.

Sequence in context: A285710 A305669 A325364 * A176615 A291453 A185660

Adjacent sequences: A133807 A133808 A133809 * A133811 A133812 A133813

KEYWORD

nonn

AUTHOR

Olivier Gérard, Sep 23, 2007

STATUS

approved