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A054212 a(n)^5 is the smallest fifth power whose decimal expansion digits occur with same frequency n. 3
0, 2955, 49995, 10365589, 75418384, 2592877410, 100661113419, 3989342709778 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Terms calculated by Jeff Heleen.

LINKS

Table of n, a(n) for n=1..8.

Patrick De Geest, Numbers whose digits occur with same frequency

EXAMPLE

2955^5 = 225313610074846875 and digits 0, 1, 2, 3, 4, 5, 6, 7, and 8 each occur twice.

PROG

(Python)

def agen(POW=5):

  n = 1

  while True:

    k = 0

    while True:

      kpowstr = str(pow(k, POW))

      q, r = divmod(len(kpowstr), n)

      if r == 0:

        ok = True

        for d in set(kpowstr):

          if kpowstr.count(d) != n:

            ok = False; break

        if ok: break

        k += 1

      else: # go to next multiple of n digits: (q+1)*n

        k = max(k+1, int((10**((q+1)*n-1))**(1/POW)))

    yield k

    n += 1

g = agen() # call with POW=4, 3, 2 for A052093, A052071, A052069

print([next(g) for n in range(1, 5)]) # Michael S. Branicky, Dec 17 2020

CROSSREFS

Cf. A054213, A052093, A052094, A052069, A052071.

Sequence in context: A178273 A289562 A054833 * A179138 A236005 A107534

Adjacent sequences:  A054209 A054210 A054211 * A054213 A054214 A054215

KEYWORD

nonn,base,hard,more

AUTHOR

Patrick De Geest, Feb 15 2000

EXTENSIONS

Offset corrected by Michel Marcus, Aug 12 2015

a(7)-a(8) from Michael S. Branicky, Dec 17 2020

STATUS

approved

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Last modified June 22 00:39 EDT 2021. Contains 345367 sequences. (Running on oeis4.)