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A109030 10-almost primes (A046314) whose digit reversal is different and also has 10 prime factors (with multiplicity). "Emirp Tsolma-10.". 3
46848, 84864, 217152, 219456, 232848, 251712, 257664, 259776, 274104, 276048, 401472, 415584, 422820, 428160, 428736, 447360, 466752, 485514, 637824, 650160, 654912, 677952, 808320, 840672, 846369, 848232, 963648 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence is the k = 10 instance of the series which begins with k = 1 (emirps), k = 2 (emirpimes), k = 3 (emirp tsolma-3 = A109023), k = 4 (emirp tsolma-4 = A109024), k = 5 (emirp tsolma-5 = A109025), k = 6 (emirp tsolma-6 = A109026), k = 7 (emirp tsolma-7 = A109027), k = 8 (emirp tsolma-8 = A109028), k = 9 (emirp tsolma-9 = A109029).

The Mathematica code for this was written by Ray Chandler who extended this sequence. He also has more values.

REFERENCES

Jonathan Vos Post, "1066 and All That: Emirp Tsolma-3 and Related Integer Sequences." Forthcoming paper on this sequence.

LINKS

Table of n, a(n) for n=1..27.

Eric Weisstein's World of Mathematics, Almost Prime.

Eric Weisstein's World of Mathematics, Emirp.

Eric Weisstein and Jonathan Vos Post, Emirpimes.

EXAMPLE

a(1) = 46848 is in this sequence because 46848 = 2^8 * 3 * 61 is a 10-almost prime and reverse(46848) = 84864 = 2^7 * 3 * 13 * 17 is also a 10-almost prime.

MATHEMATICA

taQ[n_]:=Module[{idn=IntegerDigits[n], rev}, rev=Reverse[idn]; rev!=idn&&PrimeOmega[n] == 10 == PrimeOmega[FromDigits[rev]]]; Select[Range[ 1000000], taQ] (* Harvey P. Dale, May 03 2013 *)

CROSSREFS

Cf. A046314, A006567, A097393, A109018, A109023-A109029, A109031-A109131.

Sequence in context: A066359 A234774 A236053 * A093223 A250688 A183601

Adjacent sequences:  A109027 A109028 A109029 * A109031 A109032 A109033

KEYWORD

nonn,base

AUTHOR

Jonathan Vos Post, Jun 16 2005

STATUS

approved

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Last modified October 21 02:26 EDT 2021. Contains 348141 sequences. (Running on oeis4.)