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 A240082 Numbers n such that k^n-(k-1)^n-...-3^n-2^n-1 is prime for some k. 1
 2, 3, 4, 5, 6, 7, 8, 12, 13, 16, 17, 19, 31, 34, 48, 61, 68, 72, 89, 107, 112, 124, 127, 236, 260, 288, 384, 396, 432, 520, 521, 576, 607, 1080, 1244, 1279, 1424, 1500, 1660, 2203, 2281, 2640, 2730, 2808, 3190, 3217, 4150, 4253, 4423, 4428, 5016, 5892 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These are the values of n such that A240081(n) is nonzero. LINKS PROG (Python) import sympy from sympy import isprime def Leq(n): ..for k in range(1000): ....num = k**n ....for i in range(2, k): ......num -= i**n ......if num < 1: ........return None ....if isprime(num-1): ......return k n = 1 while n < 10**3: ..if Leq(n) != None: ....print(n) ..n += 1 (PARI) f(n)=for(k=1, 10^3, num=k^n; for(i=2, k-1, num-=i^n; if(num<1, return(0))); if(ispseudoprime(num-1), return(k))); n=1; while(n<10^3, if(f(n), print(n)); n+=1) CROSSREFS Cf. A240081. Sequence in context: A119797 A032972 A210585 * A321334 A238084 A211202 Adjacent sequences:  A240079 A240080 A240081 * A240083 A240084 A240085 KEYWORD nonn AUTHOR Derek Orr, Mar 31 2014 EXTENSIONS a(34)-a(52) from Giovanni Resta, Apr 02 2014 STATUS approved

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Last modified May 25 11:27 EDT 2020. Contains 334592 sequences. (Running on oeis4.)