A065977 Numbers k that divide the number formed by the first k decimal digits of e (A039920(k)).
1, 9, 13, 15, 220, 1610, 1822, 4879, 61992, 124838, 604739, 771780, 802771, 915973, 918868, 2722883, 3466893
Offset: 1
Crossrefs
Cf. A039920.
Programs
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Mathematica
d = Drop[ First[ RealDigits[E, 10, 10^5 +1]], 1]; Do[ If[ IntegerQ[ FromDigits[Take[d, n]]/n], Print[n]], {n, 1, 65240} ] -
Python
from sympy import E digits_of_e = str(E.n(13*10**4))[2:] # or load data from file def afind(): kint = 0 for k in range(1, len(digits_of_e)): kint *= 10 kint += int(digits_of_e[k-1]) if kint%k == 0: print(k, end=", ") afind() # Michael S. Branicky, Dec 28 2022
Extensions
a(9) from Robert G. Wilson v, Dec 10 2001
a(10)-a(17) from Michael S. Branicky, Dec 28 2022