A078280 a(n) = A078279(n)/22.

2, 212, 22122, 2258577, 18913180982, 189219046321892, 1893099641364512802, 18935542777368728158257, 189400886865505550637253712, 1894918005023238233732500894622, 19367362777550568701870550728176482, 193719500503687550659615507369001321937, 1937649596364149143005250529144645910417392

Offset: 1

Author

Amarnath Murthy, Nov 25 2002

Keywords

• nonn
• base

Crossrefs

Cf. A078278, A078279, A078281.

Programs

PARI

a(n) = {my(c=vector(n), d=0, v=w=[4]); forcomposite(i=4, 4*n, c[d++]=i; if(d==n, break)); for(i=2, n, v=concat(v, d=digits(c[i])); w=concat(d, w)); fromdigits(vector(2*#v, i, if(i%2, v[1+i\2], w[i/2])))/22; } \\ Jinyuan Wang, May 17 2020

Extensions

More terms from Jinyuan Wang, May 17 2020