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A218834 Primes p such that 3*p is greater than  the greatest prime factor of  p^3 - 1 and of  p^3 + 1. 1
37, 47, 107, 211, 263, 373, 431, 521, 571, 631, 653, 719, 809, 821, 829, 941, 997, 1031, 1033, 1087, 1109, 1129, 1301, 1327, 1399, 1429, 1543, 1571, 1601, 1637, 1663, 1699, 1783, 1823, 1871, 1913, 1979, 1999, 2153, 2207, 2243, 2267, 2393, 2459, 2609, 2927 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

37^3 - 1 = 2^2*3^3*7*67, 37^3 + 1 = 2*19*31*43 and 37*3 > 43 and 37*3 > 67

MATHEMATICA

Select[Prime[Range[PrimePi[3000]]], 3 # > FactorInteger[#^3 - 1][[-1, 1]] && 3 # > FactorInteger[#^3 + 1][[-1, 1]] &] (* T. D. Noe, Nov 07 2012 *)

PROG

(PARI) forprime(h=3, 5001, for(n=3, 3, a=h^n; b=a-1; c=a+1; d=vecmax(factor(b)[, 1]~); e=vecmax(factor(c)[, 1]~); g=h*n; if(g>d && g>e, print1(h, ", "))))

CROSSREFS

Sequence in context: A159750 A108333 A231254 * A039465 A083240 A162556

Adjacent sequences:  A218831 A218832 A218833 * A218835 A218836 A218837

KEYWORD

nonn

AUTHOR

Robin Garcia, Nov 07 2012

STATUS

approved

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Last modified May 17 12:01 EDT 2021. Contains 343971 sequences. (Running on oeis4.)