

A089308


Triangle read by rows, in which nth 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
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OFFSET

1,2


COMMENTS

It is not always the case that the first n1 terms are n,n+1, n+2, ... 2n2 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



