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A036331 Composite numbers n such that juxtaposition of prime factors of n has length 7. 1
128, 192, 288, 320, 352, 416, 432, 448, 480, 528, 544, 608, 624, 648, 672, 720, 736, 792, 800, 816, 880, 912, 928, 936, 968, 972, 992, 1008, 1040, 1080, 1104, 1120, 1144, 1184, 1188, 1200, 1224, 1232, 1312, 1320, 1352, 1360, 1368, 1376, 1392, 1404, 1452 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The last term of this sequence is a(919196)=9943081.
LINKS
MAPLE
isA036331 := proc(n) local d: d:=ifactors(n)[2]: return `if`(not isprime(n) and add(length(d[j][1])*d[j][2], j=1..nops(d))=7, n, NULL): end: seq(isA036331(n), n=2..1452); # Nathaniel Johnston, Jun 22 2011
CROSSREFS
Sequence in context: A114408 A114418 A046307 * A046308 A110290 A045028
KEYWORD
nonn,base,fini,easy
AUTHOR
Patrick De Geest, Dec 15 1998
STATUS
approved

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Last modified July 15 11:27 EDT 2024. Contains 374332 sequences. (Running on oeis4.)