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A290148
a(n) is the integer resulting from the concatenation of the unit digit of n-1 to the digits of n without its own unit digit.
0
0, 1, 2, 3, 4, 5, 6, 7, 8, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 92, 2, 12, 22, 32, 42, 52, 62, 72, 82, 93, 3, 13, 23, 33, 43, 53, 63, 73, 83, 94, 4, 14, 24, 34, 44, 54, 64, 74, 84, 95, 5, 15, 25, 35, 45, 55, 65, 75, 85, 96, 6, 16, 26, 36, 46, 56, 66, 76, 86, 97, 7
OFFSET
1,3
COMMENTS
Take list of integers n >= 1, move right digit of each term to left end of next term.
FORMULA
a(n) = (n -1 mod 10)*10^A004216(n) + floor(n/10). # Robert Israel, Jul 21 2017
EXAMPLE
For n=46, n-1 is 45, so a(46) is the concatenation of 5 (the unit digit of 45) and 4 (46 without 6), giving 54.
For n=123, n-1 is 122, so a(123) is the concatenation of 2 (the unit digit of 122) and 12 (123 without 3), giving 212.
MAPLE
f:= n -> (n-1 mod 10) * 10^ilog10(n) + floor(n/10);
PROG
(PARI) a(n) = my(precd = (n-1)%10); if (n < 10, precd, eval(concat(Str(precd), Str(n\10))));
CROSSREFS
Sequence in context: A331879 A098755 A028430 * A171717 A303369 A154701
KEYWORD
nonn,base
AUTHOR
Michel Marcus, Jul 21 2017
STATUS
approved