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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
1, 3, 15, 909, 306915, 36181647, 25342642989 (list; graph; refs; listen; history; text; internal format)
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
Sequence in context: A296939 A077399 A219122 * A207332 A013409 A013408
KEYWORD
more,nonn
AUTHOR
Logan J. Kleinwaks, Oct 11 2017
STATUS
approved

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Last modified March 29 08:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)