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A104318 Primes which are the reverse concatenation of two consecutive cubes. 1

%I #16 Jan 09 2022 02:30:36

%S 6427,2700024389,6400059319,7408868921,12597121225043,29859842924207,

%T 89989128869743,92610009129329,1600300815813251,2057082420346417,

%U 2809446427818127,3930400038958219,4214419241781923,4665600046268279,6993452869426531,7303463272511713

%N Primes which are the reverse concatenation of two consecutive cubes.

%H Michael S. Branicky, <a href="/A104318/b104318.txt">Table of n, a(n) for n = 1..10000</a>

%e The first term is 6427 which is a prime and is the reverse concatenation of 27 and 64 which are two consecutive cubes.

%t rcat[{a_,b_}]:=FromDigits[Join[IntegerDigits[b],IntegerDigits[a]]]; Select[ rcat/@Partition[Range[500]^3,2,1],PrimeQ] (* _Harvey P. Dale_, Feb 21 2012 *)

%o (Python)

%o from sympy import isprime

%o def aupton(terms):

%o alst, i, s2 = [], 1, "1"

%o while len(alst) < terms:

%o i += 1

%o s1, s2 = s2, str(i**3)

%o t = int(s2+s1)

%o if isprime(t):

%o alst.append(t)

%o return alst

%o print(aupton(16)) # _Michael S. Branicky_, Jan 08 2022

%K base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Apr 17 2005

%E a(15)-a(16) from _Lorenzo Pinlac_, Jan 08 2022

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Last modified February 29 11:22 EST 2024. Contains 370425 sequences. (Running on oeis4.)