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 A255917 Triangular numbers n such that each decimal digit of n is equal to the difference of at least two other digits of n. 3
 990, 3003, 5050, 10011, 10878, 13203, 15051, 28680, 39903, 41041, 45150, 64620, 66066, 81810, 93096, 107880, 108811, 145530, 155403, 165600, 191890, 203203, 237705, 322003, 339900, 404550, 405450, 414505, 441330, 468028, 499500, 500500, 502503, 504510 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Proper subset of A255966. - Michel Marcus , Mar 13, 2015. LINKS EXAMPLE 10878 is in this sequence since it is the 147th triangular number and 1 = 8-7, 0 = 8-8, 8 = 8-0, 7 = 8-1 and 8 = 8-0, where the eights are different digits. MATHEMATICA fQ[n_] := Block[{id = IntegerDigits@ n, lng = 1 + Floor@ Log10@ n}, Union@ Table[c = Complement[ Range@ lng, {i}]; MemberQ[ Union@ Flatten@ Table[Abs[id[[j]] - id[[k]]], {j, c}, {k, c}], id[[i]]], {i, lng}] == {True}]; tri[n_] := n(n + 1)/2; Select[ tri@ Range@ 1050, fQ] CROSSREFS Cf. A000217, A255892, A255893. Sequence in context: A087702 A224565 A295768 * A154071 A218133 A295433 Adjacent sequences:  A255914 A255915 A255916 * A255918 A255919 A255920 KEYWORD base,easy,nonn AUTHOR Michel Lagneau and Robert G. Wilson v, Mar 11 2015 STATUS approved

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Last modified August 4 14:02 EDT 2020. Contains 336201 sequences. (Running on oeis4.)