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 A048363 a(n) is the index of the smallest triangular number containing exactly n 8's. 1
 7, 87, 312, 1287, 10572, 81103, 397212, 881912, 5270652, 7601169, 134021535, 421518419, 1402775027, 4204494972, 42305694389, 397212509427, 1943649189427, 6130065071251 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..18. Eric Weisstein's World of Mathematics, Triangular Number MATHEMATICA nsmall = Table[Infinity, 20]; For[i = 0, i <= 10^6, i++, p = PolygonalNumber[i]; n0 = Count[IntegerDigits[p], 8]; If[nsmall[[n0]] > i, nsmall[[n0]] = i]]; ReplaceAll[nsmall, Infinity -> "?"] (* Robert Price, Mar 22 2020 *) CROSSREFS Cf. A036525, A048355-A049364. Sequence in context: A344106 A346987 A092586 * A254473 A183613 A295036 Adjacent sequences: A048360 A048361 A048362 * A048364 A048365 A048366 KEYWORD nonn,base,more AUTHOR Patrick De Geest, Mar 15 1999 EXTENSIONS a(13)-a(15) from Lars Blomberg, May 16 2011 a(16)-a(18) from Giovanni Resta, Oct 30 2019 STATUS approved

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Last modified August 4 01:40 EDT 2024. Contains 374905 sequences. (Running on oeis4.)