A155148 Numbers k such that k^4 has exactly 2 different decimal digits.

2, 3, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000, 10000000000, 100000000000, 1000000000000, 10000000000000, 100000000000000, 1000000000000000, 10000000000000000, 100000000000000000, 1000000000000000000, 10000000000000000000, 100000000000000000000, 1000000000000000000000

Offset: 1

Author

Dmitry Kamenetsky, Jan 21 2009

Keywords

• nonn
• base

Crossrefs

Cf. A155149, A155150

Programs

Maple

for n from 1 do convert(convert(n^4,base,10),set) ; if nops(%) = 2 then print(n) ; fi; od: # R. J. Mathar, Feb 08 2009

Python

A155148_list, m = [], [24, -36, 14, -1, 0]
for n in range(1,10**6+1):
    for i in range(4):
        m[i+1] += m[i]
    if len(set(str(m[-1]))) == 2:
        A155148_list.append(n) # Chai Wah Wu, Nov 05 2014

Extensions

Two more terms from R. J. Mathar, Feb 08 2009

a(9)-a(12) from Charles R Greathouse IV, Aug 01 2010

More terms from David A. Corneth, Jun 30 2025