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A089698 Largest n-digit number k such that k+1 as well as 1 + the product of digits of k are squares greater than 1. 1
8, 35, 783, 8835, 92415, 956483, 9634815, 95413823, 941385123, 9857511224, 99575589135, 993574355523, 9553625719235, 99581119573155, 992553557213123, 9535746315113315, 96113351543713155, 993511252251119715, 9611213651115713535, 93112315591271511615, 963115211115325173135, 9621111711335151513615, 91735112131113523151523 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..23.

MAPLE

readlib(issqr): Digits:=100: for d from 1 to 15 do for n from floor(sqrt(10^d)) by -1 to ceil(sqrt(10^(d-1)+1)) 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, A089697.

Sequence in context: A000426 A250889 A200312 * A133887 A200713 A184294

Adjacent sequences:  A089695 A089696 A089697 * A089699 A089700 A089701

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 by Chai Wah Wu, Aug 14 2017

a(17) from Chai Wah Wu, Aug 16 2017

a(18)-a(23) from Chai Wah Wu, Aug 19 2017

STATUS

approved

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Last modified October 18 17:13 EDT 2019. Contains 328186 sequences. (Running on oeis4.)