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A349871
a(n) is the start of the least run of exactly n consecutive nobly abundant numbers (A349758).
0
60, 735, 1274, 28674, 19940, 1699947, 4630544, 24816974, 111500620, 262315467, 30477326444
OFFSET
1,1
COMMENTS
a(12) > 1.6*10^11, if it exists.
EXAMPLE
a(2) = 735 since 735 and 736 are the least pair of consecutive numbers that are nobly abundant numbers.
MATHEMATICA
abQ[n_] := DivisorSigma[1, n] > 2*n; nobAbQ[n_] := And @@ abQ /@ DivisorSigma[{0, 1}, n]; seq[len_, nmax_] := Module[{s = Table[0, {len}], count = 0, n = 1, n1, d}, While[n < nmax && count < len, n1 = n; If[nobAbQ[n], While[nobAbQ[++n1]]; d = n1 - n; If[d <= len && s[[d]] == 0, count++; s[[d]] = n]]; n = n1 + 1]; TakeWhile[s, # > 0 &]]; seq[6, 10^6]
CROSSREFS
Sequence in context: A138409 A024016 A348583 * A112042 A168307 A323566
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Dec 03 2021
STATUS
approved