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A089308 Triangle read by rows, in which n-th row contains n numbers starting with n and in increasing order such that the product of the terms + 1 gives the smallest such prime. 1
1, 2, 3, 3, 4, 5, 4, 5, 6, 10, 5, 6, 7, 8, 9, 6, 7, 8, 9, 10, 11, 7, 8, 9, 10, 11, 12, 14, 8, 9, 10, 11, 12, 14, 15, 16, 9, 10, 11, 12, 13, 14, 15, 16, 21, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

It is not always the case that the first n-1 terms are n,n+1, n+2, ... 2n-2 etc. and then the last term chosen to yield a prime. The choice of the terms is the one that yields the least prime.

LINKS

Table of n, a(n) for n=1..78.

EXAMPLE

1

2 3

3 4 5

4 5 6 10

5 6 7 8 9

...

a(22)..a(28)=7,8,9,10,11,12,14 is the strictly increasing sequence that yields the smallest prime A089307(7)=9313921 of the form 7*n2*n3*..*n7+1, 7<n2<...<n7.

CROSSREFS

Cf. A089307.

Sequence in context: A120246 A120244 A094727 * A305579 A321440 A115729

Adjacent sequences:  A089305 A089306 A089307 * A089309 A089310 A089311

KEYWORD

nonn,tabl

AUTHOR

Amarnath Murthy, Nov 01 2003

EXTENSIONS

More terms from Hugo Pfoertner, Apr 06 2004

STATUS

approved

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Last modified August 9 22:52 EDT 2020. Contains 336335 sequences. (Running on oeis4.)