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A188499 Intersection of A089633 and A188341. 6
1, 2, 5, 7, 23, 239 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Binomial coefficient predictors in both bases 2 and 3 (for definition, see paper in link).
Next term is > 5*10^300, if it exists.
LINKS
V. Shevelev, Binomial Coefficient Predictors, Journal of Integer Sequences, Vol. 14 (2011), Article 11.2.8.
MATHEMATICA
aQ[n_]:= DigitCount[n, 2, 0] < 2 && DigitCount[n, 3, 0] == 0 && DigitCount[n, 3, 1] < 2; Select[Range[1000], aQ] (* Amiram Eldar, Dec 10 2018 *)
PROG
(PARI) isok2(n) = my(b=binary(n)); #select(x->(x==0), b) <= 1; \\ A089633
isok3(n) = my(d=digits(n, 3)); (#select(x->(x==0), d) == 0) && (#select(x->(x==1), d) <= 1); \\ A188341
isok(n) = isok2(n) && isok3(n); \\ Michel Marcus, Dec 10 2018
CROSSREFS
Sequence in context: A099228 A182474 A106018 * A215535 A056921 A041245
KEYWORD
nonn,base,more
AUTHOR
Vladimir Shevelev, Apr 02 2011
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)