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A348187 Integers m with k digits (for some k) that lie in an interval of k integers and the digits of m are the total number of distinct prime factors of all the integers in that interval. 0
12, 22, 31, 122, 132, 312, 322, 2323, 3312, 14421, 23222, 24243, 33333, 51243, 333424, 342332, 432241, 523233, 1333232, 1432243, 2424341, 2442253, 5134334, 15232343, 24243232, 24424243, 25514234, 26134354, 32334533, 33252335, 33341415, 33343412, 34332425, 43523432, 53224343 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
12 is term because omega([11, 12]) gives [1, 2], the digits of 12.
33333 is a term because omega([33332, 33333, 33334, 33335, 33336]) but also omega([33333, 33334, 33335, 33336, 33337]) both give [3, 3, 3, 3, 3].
PROG
(PARI) vecn(n) = {my(list = List()); for (k=10^(n-1), 10^n-1-n, my(w = apply(omega, vector(n, i, k+i-1))); my(m = fromdigits(w)); if ((m>=k) && (m<=k+n-1), listput(list, m)); ); Set(list); }
lista(nn) = {my(list = List()); for (n=1, nn, my(w=vecn(n)); for (k=1, #w, listput(list, w[k])); ); Set(list); }
CROSSREFS
Cf. A001221 (omega), A323083 (following), A348266 (preceding).
Sequence in context: A078538 A278030 A286094 * A098955 A285470 A124885
KEYWORD
nonn,base
AUTHOR
Michel Marcus, Oct 12 2021
STATUS
approved

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Last modified July 14 16:11 EDT 2024. Contains 374322 sequences. (Running on oeis4.)