A138877 Concatenation of first 3 digits and last 3 digits of n-th perfect number.

66, 2828, 496496, 812128, 335336, 858056, 137328, 230128, 265176, 191216, 131128, 144128, 235976, 141128, 541328, 108528, 994776, 335056, 182536, 407528, 114216, 598576, 395336, 931656, 100376, 811816, 365456, 144528, 136528, 131016, 278128

Offset

1,1

Links

Table of n, a(n) for n=1..31.

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

Jan Munch Pedersen, Known Perfect Numbers [From Steven Bi (chenhsi(AT)stanford.edu), Jan 13 2009]

Crossrefs

Cf. A000396, A104511, A138843, A138866.

Sequence in context: A004365 A062152 A138875 * A265454 A004998 A239409

Adjacent sequences: A138874 A138875 A138876 * A138878 A138879 A138880

Keyword

base,nonn

Author

Omar E. Pol, Apr 02 2008

Extensions

Added terms 15-33 and corrected 1 term Steven Bi (chenhsi(AT)stanford.edu), Jan 13 2009

Status

approved