A224252 Nonpalindromic n such that the factorizations of n and its digital reverse differ only for the exponents order.

277816, 618772, 14339143, 34193341, 1125355221, 1225535211, 2613391326, 6231933162, 26157457326, 62375475162, 100504263021, 102407325111, 111523704201, 120362405001, 144326261443, 275603902756, 277816277816, 344162623441, 392739273927, 392875758639

Offset

1,1

Comments

Subset of A110751 and A110819.

Links

Giovanni Resta, Table of n, a(n) for n = 1..34 (terms < 2*10^12)

Example

277816 and its reverse 618772 are in the sequence since 277816 = 2^3*7*11^2*41 and 618772 = 2^2*7^3*11*41 have the same prime divisors and the same exponents (1,1,2,3).

Mathematica

Do[fn = FactorInteger@n; fr = FactorInteger@ FromDigits@ Reverse@ IntegerDigits@n; If[fn != fr && First /@ fn == First /@ fr && Sort[Last /@ fn] == Sort[Last /@ fr], Print[n]], {n, 15*10^6}]

Prog

(Python)
from sympy import primefactors, factorint
A224252 = [n for n in range(1, 10**6) if n != int(str(n)[::-1]) and primefactors(n) == primefactors(int(str(n)[::-1])) and sorted(factorint(n).values()) == sorted(factorint(int(str(n)[::-1])).values())] # Chai Wah Wu, Aug 21 2014

Crossrefs

Cf. A110751, A110819, A224253.

Sequence in context: A295472 A162765 A186879 * A236017 A252209 A043601

Adjacent sequences: A224249 A224250 A224251 * A224253 A224254 A224255

Keyword

nonn,base

Author

Giovanni Resta, Apr 02 2013

Status

approved