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A268227
a(n) = sum of digits of (2n)^2.
2
0, 4, 7, 9, 10, 1, 9, 16, 13, 9, 4, 16, 18, 19, 19, 9, 7, 13, 18, 13, 7, 18, 19, 10, 9, 7, 13, 18, 13, 16, 9, 19, 19, 18, 16, 13, 18, 22, 25, 18, 10, 19, 18, 25, 22, 9, 22, 25, 18, 19, 1, 9, 16, 13, 18, 4, 16, 27, 19, 19, 9, 25, 22, 27, 22, 16, 18, 28, 28, 18, 16, 13, 18, 13, 16, 9, 10, 19, 18
OFFSET
0,2
LINKS
H. I. Okagbue, M. O. Adamu, S. A. Iyase, A. A. Opanuga, Sequence of Integers Generated by Summing the Digits of their Squares, Indian Journal of Science and Technology, Vol 8(15), DOI: 10.17485/ijst/2015/v8i15/69912, July 2015.
MATHEMATICA
Total[IntegerDigits[#]]&/@((2*Range[0, 80])^2) (* Harvey P. Dale, Sep 14 2016 *)
PROG
(PARI) a(n) = sumdigits((2*n)^2); \\ Michel Marcus, Jul 23 2016
CROSSREFS
Bisection of A004159. Cf. A268228.
Sequence in context: A085108 A106502 A046254 * A123573 A085746 A324599
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Jan 31 2016
STATUS
approved