Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
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: A276036 A010665 A200362 * A201933 A016719 A196999
Adjacent sequences: A096288 A096289 A096290 * A096292 A096293 A096294
Jason Earls (zevi_35711(AT)yahoo.com), Jun 24 2004