login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A244547 Numbers n with nonzero digits such that n +/- the product of digits of n are both palindromes. 1
1, 2, 3, 4, 247, 252, 348, 843, 15451, 25152, 25252, 25352, 25452, 36563, 36968, 44594, 51165, 51415, 52125, 52225, 52325, 52425, 63536, 92529, 1455541, 1545451, 1595451, 1954591, 2255522, 2524752, 2525252, 2534852, 2584352, 2853582, 2856582, 3159563, 3354533, 3524753, 3534353 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..39.

EXAMPLE

247 has all digits > 0. 247 - 2*4*7 = 191 is a palindrome, and 247 + 2*4*7 = 303 is a palindrome. Thus 247 is a member of this sequence.

PROG

(PARI) rev(n)={r=""; for(i=1, #digits(n), r=concat(Str(digits(n)[i]), r)); return(eval(r))}

for(n=1, 10^7, dig=digits(n); p=prod(k=1, #dig, dig[k]); if(p!=0, mi=n-p; ma=n+p; if(rev(mi)==mi&&rev(ma)==ma, print1(n, ", "))))

CROSSREFS

Cf. A244541, A007954.

Sequence in context: A324295 A037433 A085933 * A114341 A244548 A004877

Adjacent sequences:  A244544 A244545 A244546 * A244548 A244549 A244550

KEYWORD

nonn,base

AUTHOR

Derek Orr, Jun 29 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 29 04:54 EDT 2020. Contains 338066 sequences. (Running on oeis4.)