A138833 Concatenation of n-th perfect number and n-th Mersenne prime A000668(n).

63, 287, 49631, 8128127, 335503368191, 8589869056131071, 137438691328524287, 23058430081399521282147483647, 26584559915698317446546926159538421762305843009213693951, 191561942608236107294793378084303638130997321548169216618970019642690137449562111

Offset: 1

Author

Omar E. Pol, Apr 06 2008

Keywords

• base
• nonn

Comments

a(15) has 1156 digits. - Harvey P. Dale, Jan 10 2023

Examples

			a(3)=49631 because A000396(3)=496 and A000668(3)=31.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..14

Crossrefs

Cf. A000396, A000668, A138816, A138817, A138818, A138819, A138820, A138821, A138822, A138832.

Programs

Mathematica

Module[{nn=10},FromDigits[Flatten[IntegerDigits/@#]]&/@Thread[{PerfectNumber[ Range[ nn]],2^ MersennePrimeExponent[ Range[nn]]-1}]] (* Harvey P. Dale, Jan 10 2023 *)

Extensions

Corrected and extended by Harvey P. Dale, Jan 10 2023