A181638 - OEIS

A181638

Numbers n such that bigomega(n) = reversal(n).

30, 40, 500, 600, 7000, 1100000, 2100000, 31000000, 810000000, 7100000000, 12000000000, 32000000000, 220000000000, 5200000000000, 7200000000000, 62000000000000, 820000000000000, 920000000000000, 13000000000000000, 5300000000000000000, 73000000000000000000, 240000000000000000000, 6400000000000000000000, 840000000000000000000000, 250000000000000000000000000, 65000000000000000000000000000

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OFFSET

1,1

COMMENTS

bigomega(n), also called Omega(n) is the number of prime divisors of n (counted with multiplicity) A001222.

LINKS

Table of n, a(n) for n=1..26.

EXAMPLE

7000 is in the sequence because bigomega(7000) = reversal(7000) = 7.

MATHEMATICA

Do[If[Plus @@ Last /@ FactorInteger[ n ] ==FromDigits[Reverse[IntegerDigits[n]]],

Print[n]], {n, 1, 10^9}]