A293541 - OEIS

A293541

a(1)=1; for n>1, a(n) = least integer greater than a(n-1) such that the numbers of divisors of the pairwise sums of a(1),...,a(n) are all distinct.

1, 3, 15, 909, 306915, 36181647, 25342642989

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OFFSET

1,2

LINKS

EXAMPLE

Let d(n) be the number of divisors of n. Then a(2)!=2 because d(1+1)=d(1+2)=2. a(2)=3 because d(1+1)=2, d(1+3)=3, and d(3+3)=4 are all distinct.

CROSSREFS

KEYWORD

more,nonn

AUTHOR

STATUS

approved