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A111309
Absolute difference between the sum of the odd digits and the sum of the even digits of the n-th prime.
3
2, 3, 5, 7, 2, 4, 8, 10, 1, 7, 4, 10, 3, 1, 3, 8, 14, 5, 1, 8, 10, 16, 5, 1, 16, 2, 4, 8, 10, 5, 6, 5, 11, 13, 6, 7, 13, 2, 2, 11, 17, 6, 11, 13, 17, 19, 0, 1, 3, 5, 4, 10, 5, 4, 10, 5, 1, 6, 12, 9, 7, 10, 10, 5, 7, 11, 7, 13, 6, 8, 11, 17, 4, 13, 19, 2, 4, 19, 3, 5, 6, 5, 0, 2, 8, 5, 1, 8, 9, 7, 3
OFFSET
1,1
LINKS
Ivars Peterson, Light Rings
EXAMPLE
a(9)=1 because the 9th prime is 23 and the absolute difference between 2 & 3 is 1.
MAPLE
f:= proc(n) local Lo, Le;
Lo, Le:= selectremove(type, convert(n, base, 10), odd);
abs(convert(Lo, `+`)-convert(Le, `+`))
end proc:
map(f, [seq(ithprime(i), i=1..100)]); # Robert Israel, Nov 12 2024
MATHEMATICA
f[n_] := (id = IntegerDigits[ Prime[n]]; Abs[(Plus @@ id) - 2Plus @@ Select[id, OddQ]]); Table[f[n], {n, 91}]
CROSSREFS
Sequence in context: A074464 A074463 A038194 * A007605 A077765 A078400
KEYWORD
nonn,base,changed
AUTHOR
EXTENSIONS
Edited by Charles R Greathouse IV, Aug 04 2010
STATUS
approved