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 A138833 Concatenation of n-th perfect number and n-th Mersenne prime A000668(n). 2
 63, 287, 49631, 8128127, 335503368191, 8589869056131071, 137438691328524287, 23058430081399521282147483647, 26584559915698317446546926159538421762305843009213693951, 191561942608236107294793378084303638130997321548169216618970019642690137449562111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(15) has 1156 digits. - Harvey P. Dale, Jan 10 2023 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..14 EXAMPLE a(3)=49631 because A000396(3)=496 and A000668(3)=31. MATHEMATICA Module[{nn=10}, FromDigits[Flatten[IntegerDigits/@#]]&/@Thread[{PerfectNumber[ Range[ nn]], 2^ MersennePrimeExponent[ Range[nn]]-1}]] (* Harvey P. Dale, Jan 10 2023 *) CROSSREFS Cf. A000396, A000668, A138816, A138817, A138818, A138819, A138820, A138821, A138822, A138832. Sequence in context: A158684 A063398 A359564 * A204736 A160674 A034817 Adjacent sequences: A138830 A138831 A138832 * A138834 A138835 A138836 KEYWORD base,nonn AUTHOR Omar E. Pol, Apr 06 2008 EXTENSIONS Corrected and extended by Harvey P. Dale, Jan 10 2023 STATUS approved

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Last modified March 31 20:29 EDT 2023. Contains 361672 sequences. (Running on oeis4.)