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A368407 a(n) is the least start of a run of exactly n consecutive integers with an odd number of Fermi-Dirac factors (A064547). 1
7, 16, 23, 2, 101, 135, 429, 227, 5018, 2682, 1692, 819, 184170, 175683, 93597, 117032, 300773, 466065, 2012413, 2177318, 10267248, 39069334, 25085909, 3829812, 132899228, 316564239, 391031618, 53858226, 355227517, 1484451701, 18503618566, 370565617, 52188004547, 5708850192 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
q[n_] := OddQ[Sum[DigitCount[e, 2, 1], {e, FactorInteger[n][[;; , 2]]}]]; q[1] = False; seq[len_] := Module[{s = Table[0, {len}], n = 1, count = 0, n1, d}, While[count < len, n1 = n; If[q[n], While[q[++n1]]; d = n1 - n; If[d <= len && s[[d]] == 0, count++; s[[d]] = n]]; n = n1 + 1]; s]; seq[16]
PROG
(PARI) is(n) = {my(e = factor(n)[, 2]); sum(i = 1, #e, hammingweight(e[i])) % 2; }
lista(len) = {my(s = vector(len), n = 1, count = 0, n1, d); while(count < len, n1 = n; if(is(n), n1++; while(is(n1), n1++); d = n1 - n; if(d <= len && s[d] == 0, count++; s[d] = n)); n = n1 + 1); s};
CROSSREFS
Analogous to A275509.
Sequence in context: A044059 A287369 A342743 * A044440 A114556 A136772
KEYWORD
nonn,base
AUTHOR
Amiram Eldar, Dec 23 2023
STATUS
approved

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Last modified April 22 08:40 EDT 2024. Contains 371893 sequences. (Running on oeis4.)