A076167 -id:A076167 - cp's OEIS frontend

A111309 Absolute difference between the sum of the odd digits and the sum of the even digits of the n-th prime.

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

Zak Seidov and Robert G. Wilson v, Mar 02 2005

			a(9)=1 because the 9th prime is 23 and the absolute difference between 2 & 3 is 1.

Robert Israel, Table of n, a(n) for n = 1..10000
Ivars Peterson, Light Rings

Cf. A071650, A076167.

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

f[n_] := (id = IntegerDigits[ Prime[n]]; Abs[(Plus @@ id) - 2Plus @@ Select[id, OddQ]]); Table[f[n], {n, 91}]

Edited by Charles R Greathouse IV, Aug 04 2010

A088290 Prime numbers in which the sum of the external digits = the sum of the internal digits.

Original entry on oeis.org

1021, 1087, 1201, 1223, 1289, 1447, 1559, 1627, 2053, 2143, 2389, 2503, 2659, 2749, 3041, 3221, 3467, 3557, 3917, 4051, 4073, 4231, 4253, 4297, 4523, 4567, 4657, 4679, 4703, 5443, 5623, 5689, 5779, 5869, 6521, 6701, 6857, 6947, 7193, 7283, 7351, 7621

Offset: 1

Amarnath Murthy, Sep 29 2003

			1021 is a member 1+1 = 0+2 = 2..

Robert Israel, Table of n, a(n) for n = 1..10000

Primes in A101317.

Cf. A076167.

filter:= proc(n) local L,i;
  if not isprime(n) then return false fi;
  L:= convert(n,base,10);
  L[1] + L[-1] = add(L[i],i=2..nops(L)-1)
end proc:
select(filter, [seq(i,i=101..10^4,2)]); # Robert Israel, Oct 30 2024

edidQ[n_]:=Module[{idn=IntegerDigits[n]},idn[[1]]+idn[[-1]]==Total[Most[ Rest[idn]]]]; Select[Prime[Range[169,3000]],edidQ] (* Harvey P. Dale, Apr 20 2012 *)

More terms from David Wasserman, Aug 04 2005

Offset changed by Andrew Howroyd, Sep 19 2024

cp's OEIS Frontend

A111309 Absolute difference between the sum of the odd digits and the sum of the even digits of the n-th prime.

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