A036331 - OEIS

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A036331

Composite numbers n such that juxtaposition of prime factors of n has length 7.

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

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

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

Cf. A036326-A036334.

Sequence in context: A114408 A114418 A046307 * A046308 A110290 A045028

Adjacent sequences: A036328 A036329 A036330 * A036332 A036333 A036334

KEYWORD

nonn,base,fini,easy

AUTHOR

Patrick De Geest, Dec 15 1998

STATUS

approved