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A354559
The number of terms of A354558 that are <= 10^n.
1
1, 2, 5, 13, 28, 79, 204, 549, 1509, 4231, 12072, 36426, 112589
OFFSET
1,2
COMMENTS
The data is from De Koninck et al. (2013).
LINKS
Jean-Marie De Koninck, Nicolas Doyon, and Florian Luca, Consecutive integers divisible by the square of their largest prime factors, Journal of Combinatorics and Number Theory, Vol. 5, No. 2 (2013), pp. 81-93; Researchgate link.
Jean-Marie De Koninck and Matthieu Moineau, Consecutive Integers Divisible by a Power of their Largest Prime Factor, J. Integer Seq., Vol. 21 (2018), Article 18.9.3.
Régis de la Bretèche and Sary Drappeau, Niveau de répartition des polynômes quadratiques et crible majorant pour les entiers friables, Journal of the European Mathematical Society, Vol. 22, No. 5 (2020), pp. 1577-1624; arXiv preprint, arXiv:1703.03197 [math.NT], 2017-2019.
EXAMPLE
There is one term <= 10 in A354558, 8, therefore a(1) = 1.
There are 2 terms <= 10^2 in A354558, 8 and 49, therefore a(2) = 2.
MATHEMATICA
q[n_] := FactorInteger[n][[-1, 2]] > 1; c[s_, n_] := Count[s, _?(# <= n &)]; m = 6; c[Select[Range[10^m], q[#] && q[# + 1] &], #] & /@ (10^Range[m])
CROSSREFS
Cf. A354558.
Sequence in context: A290194 A241392 A319778 * A002559 A049097 A045366
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, May 30 2022
EXTENSIONS
a(12) from Daniel Suteu, Jun 03 2022
a(13) from Daniel Suteu, Jun 05 2022
STATUS
approved