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 A089697 Smallest n-digit number k such that k+1 as well as 1 + the product of digits of k are squares greater than 1. 1
 3, 24, 168, 1443, 12543, 118335, 1223235, 11323224, 111218115, 1112622735, 11127718143, 111234256323, 1111183732128, 11112128912195, 111121198291215, 1111117422231183, 11111117364211224, 111111275555616399, 1111251521961995715, 11111411997592513155, 111111316155511267599, 1111115159292576131135, 11111135171219693125155, 111111619512137115332355 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..24. MAPLE readlib(issqr): Digits:=100: for d from 1 to 20 do for n from ceil(sqrt((10^d-1)/9+1)) to floor(sqrt(10^d)) do m:=mul(j, j=convert(n^2-1, base, 10)): if m<>0 and issqr(m+1) then printf("%d, ", n^2-1): break fi od od: # C. Ronaldo CROSSREFS Cf. A081990, A089698. Sequence in context: A354678 A104527 A058038 * A120741 A361553 A356362 Adjacent sequences: A089694 A089695 A089696 * A089698 A089699 A089700 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 10 2003 EXTENSIONS More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004 Definition clarified and a(21)-a(24) added by Chai Wah Wu, Aug 19 2017 STATUS approved

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Last modified July 22 07:42 EDT 2024. Contains 374481 sequences. (Running on oeis4.)