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A122971
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30th powers: a(n) = n^30.
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4
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OFFSET
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0,3
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LINKS
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FORMULA
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Totally multiplicative sequence with a(p) = p^30 for prime p. Multiplicative sequence with a(p^e) = p^(30e). - Jaroslav Krizek, Nov 01 2009
Dirichlet g.f.: zeta(s-30).
Sum_{n>=1} 1/a(n) = zeta(30) = 6892673020804*Pi^30/5660878804669082674070015625.
Sum_{n>=1} (-1)^(n+1)/a(n) = 536870911*zeta(30)/536870912 = 925118910976041358111*Pi^30/759790291646040068357842010112000000. (End)
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MATHEMATICA
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PROG
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(Python)
from sympy import nextprime
def is_A122971(N, k=30): # 2nd opt. arg to check for powers other than 30
p = 2
while N >= p**k:
for e in range(N):
if N % p: break
N //= p
if e % k: return False
p = nextprime(p)
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CROSSREFS
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KEYWORD
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mult,nonn,easy
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AUTHOR
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STATUS
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approved
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