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1,2
sigma_2 = A001157 is the sum of squares of divisors of n.
Table of n, a(n) for n=1..7.
a(n)= n^A001157(n).
a(1) = 1^1 = 1.
a(2) = 2^(1+4) = 32.
a(3) = 3^(1+9) = 59049.
Table[n^DivisorSigma[2, n], {n, 20}]
Cf. A001157, A100879.
Sequence in context: A054374 A221138 A017009 * A034245 A230566 A017093
Adjacent sequences: A176027 A176028 A176029 * A176031 A176032 A176033
nonn,easy
Michel Lagneau, Apr 06 2010
approved