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 A138530 Triangle read by rows: T(n,k) = sum of digits of n in base k representation, 1<=k<=n. 18
 1, 2, 1, 3, 2, 1, 4, 1, 2, 1, 5, 2, 3, 2, 1, 6, 2, 2, 3, 2, 1, 7, 3, 3, 4, 3, 2, 1, 8, 1, 4, 2, 4, 3, 2, 1, 9, 2, 1, 3, 5, 4, 3, 2, 1, 10, 2, 2, 4, 2, 5, 4, 3, 2, 1, 11, 3, 3, 5, 3, 6, 5, 4, 3, 2, 1, 12, 2, 2, 3, 4, 2, 6, 5, 4, 3, 2, 1, 13, 3, 3, 4, 5, 3, 7, 6, 5, 4, 3, 2, 1, 14, 3, 4, 5, 6, 4, 2, 7, 6, 5, 4, 3, 2, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A131383(n) = sum of n-th row; A000027(n) = T(n,1); A000120(n) = T(n,2) for n>1; A053735(n) = T(n,3) for n>2; A053737(n) = T(n,4) for n>3; A053824(n) = T(n,5) for n>4; A053827(n) = T(n,6) for n>5; A053828(n) = T(n,7) for n>6; A053829(n) = T(n,8) for n>7; A053830(n) = T(n,9) for n>8; A007953(n) = T(n,10) for n>9; A053831(n) = T(n,11) for n>10; A053832(n) = T(n,12) for n>11; A053833(n) = T(n,13) for n>12; A053834(n) = T(n,14) for n>13; A053835(n) = T(n,15) for n>14; A053836(n) = T(n,16) for n>15; A007395(n) = T(n,n-1) for n>1; A000012(n) = T(n,n). LINKS Alois P. Heinz, Rows n = 1..141, flattened Eric Weisstein's World of Mathematics, Digit Sum EXAMPLE Start of the triangle for n in base k representation: ......................1 ....................11....10 ......... ........111....11...10 ................1111...100...11..10 ..............11111...101...12..11..10 ............111111...110...20..12..11..10 ..........1111111...111...21..13..12..11..10 ........11111111..1000...22..20..13..12..11..10 ......111111111..1001..100..21..14..13..12..11..10 ....1111111111..1010..101..22..20..14..13..12..11..10 ..11111111111..1011..102..23..21..15..14..13..12..11..10 111111111111..1100..110..30..22..20..15..14..13..12..11..10, and the triangle of sums of digits starts: ......................1 .....................2...1 ......... ..........3...2...1 ...................4...1...2...1 ..................5...2...3...2...1 .................6...2...2...3...2...1 ................7...3...3...4...3...2...1 ...............8...1...4...2...4...3...2...1 ..............9...2...1...3...5...4...3...2...1 ............10...2...2...4...2...5...4...3...2...1 ...........11...3...3...5...3...6...5...4...3...2...1 ..........12...2...2...3...4...2...6...5...4...3...2...1. PROG (Haskell) a138530 n k = a138530_tabl !! (n-1) !! (k-1) a138530_row n = a138530_tabl !! (n-1) a138530_tabl = zipWith (map . flip q) [1..] a002260_tabl where    q 1 n = n    q b n = if n < b then n else q b n' + d where (n', d) = divMod n b -- Reinhard Zumkeller, Apr 29 2015 CROSSREFS Cf. A007953. See A240236 for another version. Cf. A002260. Sequence in context: A086414 A098896 A108371 * A002341 A128260 A083368 Adjacent sequences:  A138527 A138528 A138529 * A138531 A138532 A138533 KEYWORD nonn,base,tabl AUTHOR Reinhard Zumkeller, Mar 26 2008 STATUS approved

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