

A352438


Numbers k whose decimal expansion starts with the sum of the last two digits of k.


3



10, 20, 30, 40, 50, 60, 70, 80, 90, 101, 110, 202, 211, 220, 303, 312, 321, 330, 404, 413, 422, 431, 440, 505, 514, 523, 532, 541, 550, 606, 615, 624, 633, 642, 651, 660, 707, 716, 725, 734, 743, 752, 761, 770, 808, 817, 826, 835, 844, 853, 862, 871, 880, 909, 918, 927, 936, 945, 954, 963, 972, 981, 990, 1001
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OFFSET

1,1


LINKS



EXAMPLE

10 is a term because "10" starts with "1" = 1 + 0;
101 is a term because "101" starts with "1" = 0 + 1;
1019 is a term because "1019" starts with "10" = 1 + 9; etc.


MATHEMATICA

q[n_] := Module[{d = IntegerDigits[n], s, ds, nds}, s = Plus @@ d[[2 ;; 1]]; ds = IntegerDigits[s]; nds = Length[ds]; ds == d[[1 ;; nds]]]; Select[Range[10, 1001], q] (* Amiram Eldar, Mar 16 2022 *)


PROG

(Python)
def ok(n):
s = str(n)
return n > 9 and s.startswith(str(int(s[2])+int(s[1])))


CROSSREFS



KEYWORD

base,nonn


AUTHOR



STATUS

approved



