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".
The idea of A080497 to A080500 when applied to Euler's phi function i.e. on phi-torial function defined in A001783 yields A001783 itself for obvious reasons. Is there any other such example?
Table of n, a(n) for n=1..38.
a(6) = (6-1)(6-4)= 10.
Cf. A080497, A080498, A072513.
Sequence in context: A056701 A055506 A098088 * A007661 A049891 A135432
Adjacent sequences: A080497 A080498 A080499 * A080501 A080502 A080503
Amarnath Murthy, Mar 19 2003
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003