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A339673
Numbers that cannot be expressed as sum of at most nine repdigits numbers. One may not add two integers with the same repeated digit.
4
25427, 31427, 32027, 32087, 32093, 37032, 37583, 37643, 37693, 49390, 49501, 50611, 60490, 60501, 60611, 61600, 61601, 61611, 61711, 61721, 61722, 62958, 62959, 62969, 63069, 64069, 65427, 72958, 72959, 72969, 73069, 73958, 73959, 73969, 74058, 74059, 74068
OFFSET
1,1
COMMENTS
Computer solutions found by Oscar Volpatti.
LINKS
Carlos Rivera and Rodolfo Kurchan, Puzzle 1027. Integers as sum of distinct repdigits, The prime puzzles & problems connection.
EXAMPLE
8888 and 888 cannot be used in the same expression.
Examples: 25599 = 22222 + 3333 + 44, 98765 = 88888 + 7777 + 1111 + 555 + 333 + 99 + 2.
It appears that 987654 and 987650 cannot be expressed in this way.
25427 is the smallest number without solution.
Smallest solution that ends with digits from 0 to 9 (solutions from Oscar Volpatti): 0: 49390 1: 49501 2: 37032 3: 32093 4: 143204 5: 254315 6: 74106 7: 25427 8: 62958 9: 62959.
CROSSREFS
Cf. A235400.
Sequence in context: A203090 A251227 A183648 * A324635 A242141 A124997
KEYWORD
base,nonn
AUTHOR
Rodolfo Kurchan, Jan 17 2021
STATUS
approved