OFFSET
1,1
FORMULA
a(n) == 2 (mod 4).
EXAMPLE
41614 = 2 * 20807 (between 41613 = 3*11*13*97 and 41615 = 5*7*29*41).
51358 = 2 * 25679 (between 51357 = 3*17*19*53 and 51359 = 7*11*23*29).
55166 = 2 * 27583 (between 55165 = 5*11*17*59 and 55167 = 3*7*37*71).
MATHEMATICA
e[n_] := FactorInteger[n][[;; , 2]]; SequencePosition[e /@ Range[400000], {{1, 1, 1, 1}, {1, 1}, {1, 1, 1, 1}}][[;; , 1]] + 1 (* Amiram Eldar, Sep 04 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Massimo Kofler, Sep 04 2024
STATUS
approved