A240752 - OEIS

A240752

First differences of digit sums of squares, cf. A004159.

1, 3, 5, -2, 0, 2, 4, -3, -1, -8, 3, 5, 7, 0, -7, 4, 6, -10, 1, -6, 5, 7, 0, 2, -5, 6, -1, 1, -6, -4, 7, -9, 11, -5, -3, 8, 1, -6, -4, -2, 9, 2, 4, -3, -10, 1, 3, -4, -2, 0, 2, 4, 6, -1, -8, 3, 5, -2, 0, -7, 4, 6, 8, -8, -6, 5, 7, -9, 2, -5, -3, 8, 1, 3, -4

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OFFSET

1,2

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A004159(n) - A004159(n-1).

a(n) = A007953(A000290(n)) - A007953(A000290(n-1)).

a(A202089(n)+1) = 0; a(A239878(n)+1) = 1; a(A240754(n)+1) = -1.

MATHEMATICA

Differences[Total[IntegerDigits[#]]&/@(Range[0, 80]^2)] (* Harvey P. Dale, Mar 10 2019 *)

PROG