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.

8, 35, 783, 8835, 92415, 956483, 9634815, 95413823, 941385123, 9857511224, 99575589135, 993574355523, 9553625719235, 99581119573155, 992553557213123, 9535746315113315, 96113351543713155, 993511252251119715, 9611213651115713535, 93112315591271511615, 963115211115325173135, 9621111711335151513615, 91735112131113523151523

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: A250889 A200312 A339325 * 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