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A087744
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Binary and decimal representation of n concatenated.
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1
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11, 102, 113, 1004, 1015, 1106, 1117, 10008, 10019, 101010, 101111, 110012, 110113, 111014, 111115, 1000016, 1000117, 1001018, 1001119, 1010020, 1010121, 1011022, 1011123, 1100024, 1100125, 1101026, 1101127, 1110028, 1110129, 1111030, 1111131, 10000032, 10000133
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OFFSET
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1,1
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COMMENTS
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The range of the sequence is generated by the context-sensitive grammar with decimal digits as terminals, {s,x,y,z,c,u,v,L,R} as non-terminals, s as axiom and the following rules (e is the empty word): s->L1xy1R, L->e, R->e, xy->e, 0x->1u, 1x->x0, Lx->L1u, u1->1u, u0->0u, uy->uz, zi->iz for 0<=i<=9, ziR->vjR for j=i+1 and 0<=i<9, z9R->c0R, ic->vj for j=i+1 and 0<=i<9, 9c->c0, iv->vi for 0<=i<=9, uv->xy and uc->xy1.
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LINKS
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MAPLE
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a:= n-> parse(cat(convert(n, binary), n)):
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MATHEMATICA
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Table[FromDigits[Join[IntegerDigits[n, 2], IntegerDigits[n]]], {n, 30}] (* Harvey P. Dale, Dec 13 2011 *)
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PROG
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(Python)
def a(n): return int(bin(n)[2:]+str(n))
(PARI) a(n) = fromdigits(binary(n))*10^(logint(n, 10)+1) + n; \\ Kevin Ryde, Nov 10 2022
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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