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A085152 Sequence related to ABC conjecture: All prime factors of n and n+1 are <= 5. +0
22
1, 2, 3, 4, 5, 8, 9, 15, 24, 80 (list; graph; listen)
OFFSET

1,2

COMMENT

The ABC conjecture would imply that if the prime factors of A, B, C are prescribed in advance, then there is only a finite number of solutions to the equation A + B = C with gcd(A,B,C)=1 (indeed it would bound C to be no more than "roughly" the product of those primes). So in particular there ought to be only finitely many pairs of adjacent integers whose prime factors are limited to {2, 3, 5} (D. Rusin).

This sequence is complete by a theorem of Stormer. See A002071. - T. D. Noe (noe(AT)sspectra.com), Mar 03 2008

MATHEMATICA

Select[Range[10000], FactorInteger[ # (# + 1)][[ -1, 1]] <= 5 &] - T. D. Noe (noe(AT)sspectra.com), Mar 03 2008

CROSSREFS

Cf. A085153.

Sequence in context: A054181 A163077 A054168 this_sequence A120430 A152606 A057911

Adjacent sequences: A085149 A085150 A085151 this_sequence A085153 A085154 A085155

KEYWORD

nonn,fini,full

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 21 2003

EXTENSIONS

Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com), Jun 30 2003

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


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