Search: id:A088995 Results 1-1 of 1 results found. %I A088995 %S A088995 5,98,1068,1068,127185,2728361,15917834 %N A088995 Least k>0 such that the first n digits of 2^k and 5^k are identical. %C A088995 The number of matching first digits of 2^n and 5^n increases with n and forms the sequence 3,1,6,2,2,7,7,6,6,... which approaches Sqrt(10). %H A088995 T. Sillke, Powers of 2 and 5 Puzzle %e A088995 a(2) = 98: 2^98 = 316912650057057350374175801344 and 5^98 = 3155443620884047221646914261131144918692825740436\ 09201908111572265625. %t A088995 L2 = N[ Log[ 10, 2 ], 50 ]; L5 = N[ Log[ 10, 5 ], 50 ]; k = 1; Do[ While[ Take[ RealDigits[ 10^FractionalPart[ L2*k ] ][[ 1 ] ], n ] != Take[ RealDigits[ 10^FractionalPart[ L5*k ] ][[ 1 ] ], n ], k++ ]; Print[ k ], {n, 1, 10} ] %t A088995 L2 = N[ Log[ 10, 2 ], 50 ]; L5 = N[ Log[ 10, 5 ], 50 ]; k = 1; Do[ While[ Take[ RealDigits[ 10^FractionalPart[ L2*k ]][[ 1 ]], n ] != Take[ RealDigits[ 10^FractionalPart[ L5*k ]][[ 1 ]], n ], k++ ]; Print[ k ], {n, 1, 7} ] %Y A088995 Cf. A088935. %Y A088995 Cf. A010467. %Y A088995 Sequence in context: A117341 A062538 A053980 this_sequence A093749 A147539 A156276 %Y A088995 Adjacent sequences: A088992 A088993 A088994 this_sequence A088996 A088997 A088998 %K A088995 base,nonn %O A088995 1,1 %A A088995 Lekraj Beedassy (blekraj(AT)yahoo.com), Dec 01 2003 %E A088995 Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 02 2003 Search completed in 0.001 seconds