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A145376 If T(n)>=n is the nearest triangular number to n and p_n is the n-th prime, then a(n) is the least prime such that T(a(n)*p_n)-a(n)p_n is a triangular number 1

%I #8 Jan 01 2020 21:54:02

%S 3,2,2,2,2,3,5,5,7,11,11,11,13,17,17,19,23,23,23,29,29,29,31,37,37,41,

%T 41,41,41,43,53,53,53,59,59,61,67,67,67,71,73,73,79,79,83,83,89,97,97,

%U 97,97,101,101,107,107,113,113,127,127,127,127,127,131,137

%N If T(n)>=n is the nearest triangular number to n and p_n is the n-th prime, then a(n) is the least prime such that T(a(n)*p_n)-a(n)p_n is a triangular number

%C Conjecture. For n>=2 the sequence is nondecreasing.

%C The conjecture holds for the first 10000 terms. [_Charles R Greathouse IV_, Feb 21 2011]

%H Charles R Greathouse IV, <a href="/A145376/b145376.txt">Table of n, a(n) for n = 1..10000</a>

%Y Cf. A000217, A145043, A145016, A145281, A145300.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Oct 09 2008

%E a(27)-a(64) from _Charles R Greathouse IV_, Feb 21 2011

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Last modified April 25 11:06 EDT 2024. Contains 371967 sequences. (Running on oeis4.)