A215028 a(1) = 1; for n >= 1, a(n+1) = (concatenation of n+1 and n) - a(n).
1, 20, 12, 31, 23, 42, 34, 53, 45, 64, 1046, 165, 1147, 266, 1248, 367, 1349, 468, 1450, 569, 1551, 670, 1652, 771, 1753, 872, 1854, 973, 1955, 1074, 2056, 1175, 2157, 1276, 2258, 1377, 2359, 1478, 2460, 1579, 2561, 1680, 2662, 1781, 2763, 1882, 2864, 1983
Offset: 1
Programs
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Maple
f:=proc(i) (i+1)*10^(1+floor(evalf(log10(i))))+i; end: # A127423 a:=proc(n) option remember; global f; if n=1 then 1 else f(n-1)-a(n-1); fi; end;
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PARI
A215028(n, print_all=0)={my(a=1); for(n=1, n-1, print_all & print1(a","); a=(n+1)*10^#Str(n)+n-a); a} \\ M. F. Hasler, Aug 23 2012
Comments