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Conjecture: a(n) = a(n+1) for infinitely many positive integers. Largest found is n=2577, i.e. sd(pnd(2577^2577)) = sd(pnd(2578^2578)) = 18315.
Table of n, a(n) for n=1..64.
Cf. A051801, A007953.
Sequence in context: A106593 A010665 A200362 * A201933 A016719 A196999
Adjacent sequences: A096288 A096289 A096290 * A096292 A096293 A096294
Jason Earls (zevi_35711(AT)yahoo.com), Jun 24 2004