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A133810 Numbers that are primally tight and have weakly ascending powers. 5
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
PROG
(Haskell)
a133810 n = a133810_list !! (n-1)
a133810_list = 1 : filter f [2..] where
f x = (and $ zipWith (<=) eps $ tail eps) &&
(all (== 1) $ zipWith (-) (tail ips) ips)
where ips = map a049084 $ a027748_row x
eps = a124010_row x
-- Reinhard Zumkeller, Nov 07 2012
CROSSREFS
Sequence in context: A285710 A305669 A325364 * A176615 A291453 A185660
KEYWORD
nonn
AUTHOR
Olivier Gérard, Sep 23, 2007
STATUS
approved

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Last modified February 21 22:50 EST 2024. Contains 370239 sequences. (Running on oeis4.)