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A358667
T(n,k) is the k-th integer j > 1 such that the sum of digits of n^j is a power of n (or -1 if no such k-th integer exists); table read by downward antidiagonals.
0
2, 3, 2, 4, 3, 2, 5, 9, 3, 18, 6, 36, 4, 88, 8, 7, 85, 5, 97, 208, 7, 8, 176, 9, 100, 977, 8, 4, 9, 194, 10, 1521, 1007, 9, 11, 3, 10, 200, 11, 6034, 4938, 10, 4433, 12, 2, 11, 375, 13, 6052, 24709, 13, 30810, 125, 18, 2, 12, 1517, 16, 96867, 24733, 51, 216613, 1014, 1503, 3
OFFSET
1,1
COMMENTS
T(11,1) is unknown at this time.
FORMULA
T(n,1) = A358633(n).
T(1,k) = k+1.
T(2,k) = A095412(k+2).
T(3,k) = A118872(k+2).
EXAMPLE
Table begins:
.
n\k| 1 2 3 4 5 6 7 8 9 10 11 ...
---+------------------------------------------------------------------
1 | 2 3 4 5 6 7 8 9 10 11 12 ...
2 | 2 3 9 36 85 176 194 200 375 1517 ...
3 | 2 3 4 5 9 10 11 13 16 ...
4 | 18 88 97 100 1521 6034 6052 96867 ...
5 | 8 208 977 1007 4938 24709 24733 ...
6 | 7 8 9 10 13 51 ...
7 | 4 11 4433 30810 216613 ...
8 | 3 12 125 1014 ...
9 | 2 18 1503 ...
10 | 2 3 ...
11 | ? ...
... | ...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Jon E. Schoenfield, Nov 25 2022
STATUS
approved