A124068
Fixed points for operation of repeatedly replacing a number with the sum of the seventh power of its digits.
Original entry on oeis.org
0, 1, 1741725, 4210818, 9800817, 9926315, 14459929
Offset: 1
1741725 = 1^7 + 7^7 + 4^7 + 1^7 + 7^7 + 2^7 + 5^7.
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isok(n) = my(d = digits(n)); sum(k=1, #d, d[k]^7) == n; \\ Michel Marcus, Feb 21 2015
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for(n=0,41205040,A123253(n)==n&&print1(n",")) \\ M. F. Hasler, Apr 12 2015
A355708
Irregular triangle read by rows in which row n lists the possible periods for the iterations of the map sum of n-th powers of digits.
Original entry on oeis.org
1, 1, 8, 1, 2, 3, 1, 2, 7, 1, 2, 4, 6, 10, 12, 22, 28, 1, 2, 3, 4, 10, 30, 1, 2, 3, 6, 12, 14, 21, 27, 30, 56, 92, 1, 25, 154, 1, 2, 3, 4, 8, 10, 19, 24, 28, 30, 80, 93, 1, 6, 7, 17, 81, 123
Offset: 1
Triangle begins:
1;
1, 8;
1, 2, 3;
1, 2, 7;
1, 2, 4, 6, 10, 12, 22, 28;
1, 2, 3, 4, 10, 30;
1, 2, 3, 6, 12, 14, 21, 27, 30, 56, 92;
1, 25, 154;
1, 2, 3, 4, 8, 10, 19, 24, 28, 30, 80, 93;
1, 6, 7, 17, 81, 123;
...
Showing 1-2 of 2 results.
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