STATUS
proposed
approved
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Revision History for A320633
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STATUS
editing
proposed
NAME
allocated for Gus WisemanComposite numbers whose prime indices are also composite.
DATA
49, 91, 133, 161, 169, 203, 247, 259, 299, 301, 329, 343, 361, 371, 377, 427, 437, 481, 497, 511, 529, 551, 553, 559, 611, 623, 637, 667, 679, 689, 703, 707, 721, 749, 791, 793, 817, 841, 851, 893, 917, 923, 931, 949, 959, 973, 989, 1007, 1027, 1043, 1057
OFFSET
1,1
COMMENTS
A prime index of n is a number m such that prime(m) divides n.
EXAMPLE
The sequence of terms begins:
49 = prime(4)^2
91 = prime(4)*prime(6)
133 = prime(4)*prime(8)
161 = prime(4)*prime(9)
169 = prime(6)^2
203 = prime(4)*prime(10)
247 = prime(6)*prime(8)
259 = prime(4)*prime(12)
299 = prime(6)*prime(9)
301 = prime(4)*prime(14)
329 = prime(4)*prime(15)
343 = prime(4)^3
361 = prime(8)^2
371 = prime(4)*prime(16)
377 = prime(6)*prime(10)
427 = prime(4)*prime(18)
437 = prime(8)*prime(9)
481 = prime(6)*prime(12)
497 = prime(4)*prime(20)
511 = prime(4)*prime(21)
529 = prime(9)^2
551 = prime(8)*prime(10)
553 = prime(4)*prime(22)
559 = prime(6)*prime(14)
611 = prime(6)*prime(15)
623 = prime(4)*prime(24)
637 = prime(4)^2*prime(6)
MATHEMATICA
Select[Range[2, 1000], And[OddQ[#], !PrimeQ[#], And@@Not/@PrimeQ/@PrimePi/@First/@FactorInteger[#]]&]
CROSSREFS
KEYWORD
allocated
nonn
AUTHOR
Gus Wiseman, Oct 18 2018
STATUS
approved
editing
NAME
allocated for Gus Wiseman
KEYWORD
allocated
STATUS
approved