Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #22 Sep 30 2024 15:21:33
%S 1,4,16,64,37,13,52,69,65,30,21,84,133,150,126,162,131,64,77,177,191,
%T 164,139,301,225,113,266,197,231,269,209,275,404,450,443,371,426,332,
%U 461,487,413,288,266,396,346,382,426,404,463,393,514,528,517,569,584
%N Sum of squares of the decimal digits of 2^n.
%F a(n) = A003132(A000079(n)).
%e For n=4, 2^4 = 16 and those digits 1^2 + 6^2 = 37 = a(4).
%t a[n_]:=Norm[IntegerDigits[2^n]]^2; Array[a,55,0] (* _Stefano Spezia_, Sep 06 2024 *)
%o (PARI) a(n) = norml2(digits(2^n)); \\ _Michel Marcus_, Sep 06 2024
%o (Python)
%o def A375976(n): return sum((0, 1, 4, 9, 16, 25, 36, 49, 64, 81)[int(d)] for d in str(1<<n) if d>'0') # _Chai Wah Wu_, Sep 30 2024
%Y Cf. A000079, A003132, A001370, A110892.
%K nonn,base,easy
%O 0,2
%A _Luca Khan_, Sep 04 2024