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 A282109 Numbers n with k digits in base x (MSD(n)=d_k, LSD(n)=d_1) such that, chosen one of their digits in position d_k < j < d_1, is Sum_{i=j+1..k}{(i-j)*d_i} = Sum_{i=1..j-1}{(j-i)*d_i}. Case x = 4. 3
 17, 21, 25, 29, 34, 38, 42, 46, 51, 55, 59, 63, 66, 68, 70, 74, 78, 83, 84, 87, 91, 95, 100, 116, 129, 136, 145, 152, 161, 168, 177, 184, 197, 204, 213, 220, 229, 236, 245, 252, 257, 259, 263, 264, 267, 271, 272, 273, 280, 289, 296, 305, 312, 325, 332, 336, 341 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All the palindromic numbers in base 4 with an odd number of digits belong to the sequence. Here the fulcrum is one of the digits while in the sequence from A282143 to A282151 is between two digits. LINKS Paolo P. Lava, Table of n, a(n) for n = 1..10000 EXAMPLE 83 in base 4 is 1103. If j = 2 (digit 0) we have 1*1 + 1*2 = 3 for the left side and 3*1 = 3 for the right one. MAPLE P:=proc(n, h) local a, j, k: a:=convert(n, base, h): for k from 1 to nops(a)-1 do if add(a[j]*(k-j), j=1..k)=add(a[j]*(j-k), j=k+1..nops(a)) then RETURN(n); break: fi: od: end: seq(P(i, 4), i=1..10^3); CROSSREFS A282107, A282108, A282110 - A282115. Sequence in context: A039502 A039505 A166875 * A307863 A128546 A188200 Adjacent sequences:  A282106 A282107 A282108 * A282110 A282111 A282112 KEYWORD base,nonn,easy AUTHOR Paolo P. Lava, Feb 06 2017 STATUS approved

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Last modified September 27 19:34 EDT 2021. Contains 347694 sequences. (Running on oeis4.)