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A234961 Number of primes in level n of the tree generated at A234960. 3
1, 2, 2, 4, 6, 9, 15, 22, 34, 55, 84, 140, 240, 386, 657, 1097, 1788, 2968, 4949, 8182, 13678, 22867, 38003, 63339, 105786, 175926, 293583 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..27.

MATHEMATICA

t = NestList[DeleteDuplicates[Flatten[Map[{#, NextPrime[2 #, -1], NextPrime[2 #, 1]} &, #]]] &, {2}, 26]; g = Join[{{2}}, Map[Complement[t[[# + 1]], t[[#]]] &, Range[Length[t] - 1]]]; Map[Length, g] (* A234961 *) (* Peter J. C. Moses, Dec 30 2013 *)

CROSSREFS

Cf. A234960, A234962.

Sequence in context: A293552 A293546 A052012 * A018061 A304778 A173495

Adjacent sequences:  A234958 A234959 A234960 * A234962 A234963 A234964

KEYWORD

nonn,more

AUTHOR

Clark Kimberling, Jan 01 2014

STATUS

approved

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Last modified June 20 02:34 EDT 2021. Contains 345154 sequences. (Running on oeis4.)