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A082940 Palindromes in A082939. 3

%I #31 Aug 15 2022 15:30:43

%S 1,2,22,141,171,202,333,2002,2772,7227,10401,10701,12221,13131,14841,

%T 15651,16461,17271,20002,21212,25452,26262,27072,30303,31113,33633,

%U 35253,41814,51615,52425,53235,55755,58185,61416,62226,66366,69696,71217,72027,85158,96669,117711

%N Palindromes in A082939.

%H Michael S. Branicky, <a href="/A082940/b082940.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..670 from J.W.L. (Jan) Eerland)

%e 22 = 2!*2! = 4 and 2 + 2 = 4.

%e 141 = 1!*4!*1! = 24; 2 + 4 = 6 and 1 + 4 + 1 = 6.

%t DeleteCases[ParallelTable[If[PalindromeQ[n]&&Total@IntegerDigits[Times@@Map[Factorial,IntegerDigits[n]]]==Total@IntegerDigits[n],n,a],{n,0,10^8}],a] (* _J.W.L. (Jan) Eerland_, Dec 26 2021 *)

%o (Python)

%o from math import factorial, prod

%o from itertools import count, islice, product

%o def isA082939(n):

%o d = list(map(int, str(n)))

%o return sum(map(int, str(prod(map(factorial, d))))) == sum(d)

%o def pals(): # generator of terms

%o digits = "0123456789"

%o for d in count(1):

%o for p in product(digits, repeat=d//2):

%o if d > 1 and p[0] == "0": continue

%o left = "".join(p); right = left[::-1]

%o for mid in [[""], digits][d%2]:

%o yield int(left + mid + right)

%o def agen(): yield from filter(isA082939, pals())

%o print(list(islice(agen(), 42))) # _Michael S. Branicky_, Aug 15 2022

%Y Intersection of A002113 and A082939.

%K nonn,base

%O 1,2

%A Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 27 2003, following a suggestion by _Amarnath Murthy_.

%E Corrected and extended by _J.W.L. (Jan) Eerland_, Dec 26 2021

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Last modified April 16 05:35 EDT 2024. Contains 371697 sequences. (Running on oeis4.)