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A332952 Squarefree semiprimes which never occur in A245486. 1
46, 58, 74, 94, 106, 118, 122, 134, 142, 158, 166, 194, 202, 206, 214, 262, 267, 274, 278, 298, 309, 314, 326, 334, 339, 346, 358, 362 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also squarefree semiprimes which never occur in A332951.

This sequence is infinite. It appears that all terms can be divisible by 2 or 3.

If A014664(i) = A014664(j) for some 1 < i < j, then 2*prime(i) is a term. See A245486 for more information.

LINKS

Table of n, a(n) for n=1..28.

Romanian Master in Mathematics Contest, Bucharest, 2020, Problem 6

EXAMPLE

a(2) = 58 because when 2^m - 1 or 2^m + 1 is divisible by 29, it's also divisible by 113. Therefore, there's no integer k such that A245486(k) = A006530(k) * A006530(k+1) = 58.

CROSSREFS

Cf. A000040, A006530, A006881, A014664, A245486, A332951.

Sequence in context: A119385 A330243 A326646 * A308099 A308252 A322161

Adjacent sequences:  A332949 A332950 A332951 * A332953 A332954 A332955

KEYWORD

nonn,more

AUTHOR

Jinyuan Wang, Mar 04 2020

STATUS

approved

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Last modified November 30 05:12 EST 2021. Contains 349419 sequences. (Running on oeis4.)