A109182 - OEIS

%I #7 Jul 21 2021 13:49:44

%S 293,2106,2161,2763,3698,3793,3795,3812,3922,3959,3995,4000,4205,4224,

%T 4260,4728,4953,5065,5283,5617,5700,5751,5932,6326,6333,6422,6539,

%U 6623,7375,7475,7501,7533,7542,8306,8568,8751,8777,8994,9102,9259,9354,9480

%N Numbers k such that the k-th and (k+1)-th primes have the same sum of squares of digits.

%C Most of the pairs of successive primes also have the same set of digits. Those with different sets of digits are in A109183; the first relative numbers k are 3795, 3995, 10234, 17125, 18134, 19322, 20979.

%e prime(293)=1913, prime(294)=1931; both have the same sum of digits squared: 1^2 + 9^2 + 1^2 + 3^2 = 1^2 + 9^2 + 3^2 + 1^2 = 92.

%t SequencePosition[Table[Total[IntegerDigits[Prime[n]]^2],{n,10000}],{x_,x_}][[All,1]] (* _Harvey P. Dale_, Jul 21 2021 *)

%Y Cf. A109183.

%K base,nonn

%O 1,1

%A _Zak Seidov_, Jun 21 2005