A202147
Numbers k such that the sum of digits^4 of k equals Sum_{d|k, 1
Original entry on oeis.org
1005, 5405, 89195, 92029, 107707, 149851, 323723, 524371, 610171, 999643, 1119253, 1134227, 1728787, 1900523, 2045171, 2170451, 2668381, 3351833, 3361717, 3611227, 5364059, 6571483, 7710883, 7865659, 8938691, 9286331, 9362051, 9593833, 10841387, 11507813
Offset: 1
1005 is in the sequence because 1^4 + 0^4 + 0^4 + 5^4 = 626, and the sum of the divisors 1< d<1005 is 3 + 5 +15 + 67 + 201+ 335 = 626.
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Q[n_]:=Module[{a=Total[Rest[Most[Divisors[n]]]]}, a == Total[IntegerDigits[n]^4]]; Select[Range[2, 10^7], Q]
A202285
Numbers k such that the sum of digits^5 of k equals Sum_{d|k, 1
Original entry on oeis.org
118678, 459385, 4150651, 4351003, 15033631, 20402671, 33224707, 35188159, 40460929, 42454261, 50067673, 54610051, 62004127, 77278261, 88720939, 106412347, 113660551, 113852653, 118203559, 121732873, 125252137, 128083639, 162748279, 163869049, 164863987
Offset: 1
k=118678 is in the sequence because 1^5 + 1^5 + 8^5 + 6^5 + 7^5 + 8^5 = 90121, and the sum of the divisors 1 < d < k = sigma(k) - k - 1 = 90121.
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Q[n_]:=Module[{a=Total[Rest[Most[Divisors[n]]]]}, a == Total[IntegerDigits[n]^5]]; Select[Range[2, 10^7], Q]
a(11)-a(25) and keywords fini and full added by
Giovanni Resta, Oct 05 2018
A202240
a(n) is the smallest number k such that the sum of the n-th powers of the digits of k equals the sum of the divisors of k other than 1 and k.
Original entry on oeis.org
125, 142, 1005, 118678, 706862, 18481615, 122003411, 30330043, 5923078409, 22110133333, 120175787632, 5971473681952
Offset: 2
a(5) = 118678 because 1^5 + 1^5 + 8^5 + 6^5 + 7^5 + 8^5 = 90121, and sum of the divisors 1 < d < a(5) = sigma(118678) - 118678 - 1 = 90121.
Cf.
A070308 (n=2, "Canada perfect numbers").
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f(k, n) = my(d=digits(k)); sum(i=1, #d, d[i]^n);
a(n) = my(k=1); while(f(k, n) != sigma(k)-k-1, k++); k; \\ Michel Marcus, Sep 29 2018
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