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A133809 Numbers that are primally tight, have 2 as first prime and strictly ascending powers. 2
1, 2, 4, 8, 16, 18, 32, 54, 64, 108, 128, 162, 256, 324, 486, 512, 648, 972, 1024, 1458, 1944, 2048, 2250, 2916, 3888, 4096, 4374, 5832, 8192, 8748, 11250, 11664, 13122, 16384, 17496, 23328, 26244, 32768, 33750, 34992, 39366, 52488, 56250, 65536 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

All numbers of the form 2^k1*p_2^k2*...*p_n^k_n, where k1 < k2 < ... < k_n and the p_i are the n first primes.

Subset of A073491, A133811 and A133808.

Null

CROSSREFS

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

Sequence in context: A072462 A088827 A076057 * A128700 A184986 A018547

Adjacent sequences:  A133806 A133807 A133808 * A133810 A133811 A133812

KEYWORD

nonn

AUTHOR

Olivier Gerard (olivier.gerard(AT)gmail.com), Sep 23, 2007

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Last modified February 15 11:57 EST 2012. Contains 205782 sequences.