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A328459
Sorted positions of first appearances in A328458 (maximum run-length of nontrivial divisors) of each positive integer in the image.
1
1, 2, 6, 12, 60, 420, 504, 840, 2520, 27720, 360360, 720720, 4084080
OFFSET
0,2
EXAMPLE
The sequence of terms > 1 together with their nontrivial divisors begins:
2: {}
6: {2,3}
12: {2,3,4,6}
60: {2,3,4,5,6,10,12,15,20,30}
420: {2,3,4,5,6,7,10,12,14,15,20,21,28,30,35,42,60,70,84,105,140,210}
504: {2,3,4,6,7,8,9,12,14,18,21,24,28,36,42,56,63,72,84,126,168,252}
MATHEMATICA
dav=Table[Switch[n, 1, 1, _, Max@@Length/@Split[DeleteCases[Divisors[n], 1|n], #2==#1+1&]], {n, 1000}];
Table[Position[dav, i][[1, 1]], {i, Union[dav]}]//Sort
CROSSREFS
Positions of first appearances in A328458.
The version for all divisors is A051451.
Sequence in context: A048803 A068625 A162935 * A051451 A090951 A168262
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Oct 17 2019
EXTENSIONS
a(12) from Robert Israel, Mar 31 2023
STATUS
approved