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A061597 Product of digits + 1 is prime, product of digits - 1 is prime, sum of digits + 1 is prime, sum of digits - 1 is prime and product of digits = sum of digits. 1
4, 6, 22, 123, 132, 213, 231, 312, 321, 111126, 111162, 111216, 111261, 111612, 111621, 112116, 112161, 112611, 116112, 116121, 116211, 121116, 121161, 121611, 126111, 161112, 161121, 161211, 162111, 211116, 211161, 211611, 216111, 261111, 611112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..81

EXAMPLE

22 belong to the sequence because (2*2)+1=5, (2*2)-1=3, (2+2)+1=5, (2+2)-1=3 and 2+2=2*2.

PROG

(PARI) SumD(x)= s=0; while (x>9, s=s+x-10*(x\10); x=x\10); s + x

ProdD(x)=p=1; while (x>9, p=p*(x-10*(x\10)); x=x\10); p*x

x=9; for (n=0, 78, until(s==p && isprime(s+1) && isprime(s-1) && isprime(p+1) && isprime(p-1), x++; s=SumD(x); p=ProdD(x)); write("b061597.txt", n, " ", x)) \\ Harry J. Smith, Jul 25 2009; does not produce the terms 4 and 6

CROSSREFS

Sequence in context: A061595 A062940 A061596 * A075813 A107952 A004032

Adjacent sequences:  A061594 A061595 A061596 * A061598 A061599 A061600

KEYWORD

nonn,base

AUTHOR

Felice Russo, May 22 2001

EXTENSIONS

4 and 6 added by Abdul Gaffar Khan, Nov 29 2015

STATUS

approved

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Last modified January 26 20:11 EST 2020. Contains 331288 sequences. (Running on oeis4.)