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A119447 Leading diagonal of triangle A119446, as described in A100461, except with a(1,n) = prime(n) instead of 2^(n-1). 2
2, 2, 3, 3, 3, 3, 3, 3, 3, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 13, 13, 7, 7, 7, 7, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(181) = 27 is the first term greater than 19. This is because prime(181)/181 > 6 for the first time. In general this sequence is determined by prime(n)/n: the pattern for each row of the triangle is that it ends with prime(n), preceded by multiples of k = prime(n)/n down to k^2, then the largest multiple of k-1 less than k^2 and the largest multiple of k-2 less than that and so on. This sequence gives the multiple of 1. See A000960 for the sequence that gives the ending value for each starting k.

LINKS

Table of n, a(n) for n=1..79.

FORMULA

With k = prime(n)/n, a(n) = A000960(k).

CROSSREFS

Cf. A100461 for powers of 2, A119444 for Fibonacci and A119446 for triangle corresponding to this diagonal.

Sequence in context: A130147 A096143 A025792 * A157720 A077463 A084556

Adjacent sequences:  A119444 A119445 A119446 * A119448 A119449 A119450

KEYWORD

nonn

AUTHOR

Joshua Zucker, May 20 2006

STATUS

approved

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Last modified July 13 05:18 EDT 2020. Contains 335673 sequences. (Running on oeis4.)